Organometallic compound, organic light-emitting device including the same, and electronic apparatus including the organic light-emitting device

ABSTRACT

Provided are an organometallic compound represented by Formula 1, an organic light-emitting device including the same, and an electronic apparatus comprising the organic light-emitting device:M(L1)n1(L2)n2  Formula 1wherein, in Formula 1, M, L1, L2, n1, and n2 are the same as described in the detailed description of the specification.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation application of U.S. application Ser. No. 16/808,605, filed on Mar. 4, 2020, which claims priority to and the benefit of Korean Patent Applications No. 10-2019-0026320, filed on Mar. 7, 2019, and 10-2020-0026887, filed on Mar. 4, 2020, in the Korean Intellectual Property Office, the contents of which are incorporated herein in their entirety by reference.

BACKGROUND 1. Field

One or more embodiments relate to an organometallic compound, an organic light-emitting device including the organometallic compound, and an electronic apparatus including the organic light-emitting device.

2. Description of the Related Art

Organic light-emitting devices are self-emission devices, which have better characteristics in terms of a viewing angle, response time, brightness, driving voltage, and response speed, and produce full-color images.

In an example, an organic light-emitting device includes an anode, a cathode, and an organic layer between the anode and the cathode, wherein the organic layer includes an emission layer. A hole transport region may be between the anode and the emission layer, and an electron transport region may be between the emission layer and the cathode. Holes provided from the anode may move toward the emission layer through the hole transport region, and electrons provided from the cathode may move toward the emission layer through the electron transport region. The holes and the electrons recombine in the emission layer to produce excitons. These excitons transit from an excited state to a ground state, thereby generating light.

SUMMARY

Aspects of the present disclosure provide an organometallic compound, an organic light-emitting device including the organometallic compound, and an electronic apparatus including the organic light-emitting device.

Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments.

An aspect of the present disclosure provides an organometallic compound represented by Formula 1 below:

M(L₁)_(n1)(L₂)_(n2).  Formula 1

In Formula 1,

-   -   M may be a transition metal,     -   L₁ may be a ligand represented by Formula 2A,     -   L₂ may be a ligand represented by Formula 2B,     -   n1 and n2 may each independently be 1 or 2, wherein, when n1 is         2, two L₁(s) may be identical to or different from each other         and when n2 is 2, two L₂(s) may be identical to or different         from each other,     -   the sum of n1 and n2 may be 2 or 3, and     -   L₁ to L₂ may be different from each other:

In Formulae 2A and 2B,

-   -   Y₁ and Y₄ may each independently be C or N,     -   X₁ may be Si or Ge,     -   X₂₁ may be O, S, S(═O), N(Z₂₉), C(Z₂₉)(Z₃₀), or Si(Z₂₉)(Z₃₀),     -   T₁ to T₄ may each independently be C, N, carbon linked to ring         CY₁, or carbon linked to M in Formula 1, wherein one of T₁ to T₄         may be carbon linked to M in Formula 1, and one of the remaining         T₁ to T₄ that are not linked to M in Formula 1 may be carbon         linked to ring CY₁,     -   T₅ to T₈ may each independently be C or N,     -   when X₁ is Si, at least one of the remaining T₁ to T₈ that are         not carbon linked to M and ring CY₁ may be N,     -   ring CY₁ and ring CY₁₄ may each independently be a C₅-C₃₀         carbocyclic group or a C₁-C₃₀ heterocyclic group,     -   R₂₁ to R₂₃ may each independently be a C₁-C₆₀ alkyl group or a         C₆-C₆₀ aryl group, each unsubstituted or substituted with         deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H,         —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino         group, an amidino group, a hydrazine group, a hydrazone group, a         carboxylic acid group or a salt thereof, a sulfonic acid group         or a salt thereof, a phosphoric acid group or a salt thereof, a         C₁-C₆₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a phenyl group,         or any combination thereof,     -   Z₁, Z₂, and R₁₁ to R₁₄ may each independently be hydrogen,         deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano         group, a nitro group, an amino group, an amidino group, a         hydrazine group, a hydrazone group, a carboxylic acid group or a         salt thereof, a sulfonic acid group or a salt thereof, a         phosphoric acid group or a salt thereof, a substituted or         unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted         C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀         alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy         group, a substituted or unsubstituted C₁-C₆₀ alkylthio group, a         substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a         substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a         substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a         substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a         substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or         unsubstituted C₆-C₆₀ aryloxy group, a substituted or         unsubstituted C₆-C₆₀ arylthio group, a substituted or         unsubstituted C₁-C₆₀ heteroaryl group, a substituted or         unsubstituted monovalent non-aromatic condensed polycyclic         group, a substituted or unsubstituted monovalent non-aromatic         condensed heteropolycyclic group, —N(Q₁)(Q₂), —Ge(Q₃)(Q₄)(Q₅),         —B(Q₆)(Q₇), —P(═O)(Q₈)(Q₉) or —P(Q₈)(Q₉), wherein R₁₂ is neither         hydrogen nor a methyl group,     -   a1 and b1 may each independently be an integer from 0 to 20,         wherein, when a1 is 2 or more, two or more Z₁(s) may be         identical or different, and when b1 is 2 or more, two or more         R₁₄(s) may be identical or different,     -   a2 may be an integer from 0 to 6, wherein, when a2 is 2 or more,         two or more Z₂(s) may be identical to or different from each         other,     -   two or more of R₂₁ to R₂₃ may optionally be linked to form a         C₅-C₃₀ carbocyclic group that is unsubstituted or substituted         with at least one R_(10a) or a C₁-C₃₀ heterocyclic group that is         unsubstituted or substituted with at least one R_(10a),     -   two or more of a plurality of Z₁(s) may optionally be linked to         form a C₅-C₃₀ carbocyclic group that is unsubstituted or         substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic         group that is unsubstituted or substituted with at least one         R_(10a),     -   two or more of a plurality of Z₂(s) may optionally be linked to         form a C₅-C₃₀ carbocyclic group that is unsubstituted or         substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic         group that is unsubstituted or substituted with at least one         R_(10a),     -   R₁₂ and R₁₃ may optionally be linked to form a C₅-C₃₀         carbocyclic group that is unsubstituted or substituted with at         least one R_(10a) or a C₁-C₃₀ heterocyclic group that is         unsubstituted or substituted with at least one R_(10a),     -   two or more of a plurality of R₁₄(s) may optionally be linked to         form a C₅-C₃₀ carbocyclic group that is unsubstituted or         substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic         group that is unsubstituted or substituted with at least one         R_(10a),     -   two or more of Z₁, Z₂ and R₁₁ to R₁₄ may optionally be linked to         form a C₅-C₃₀ carbocyclic group that is unsubstituted or         substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic         group that is unsubstituted or substituted with at least one         R_(10a),     -   R_(10a) may be the same as defined in connection with R₁₄,     -   * and *′ in Formulae 2A and 2B each indicate a binding site to M         in Formula 1,     -   a substituent of the substituted C₁-C₆₀ alkyl group, the         substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl         group, the substituted C₁-C₆₀ alkoxy group, the substituted         C₁-C₆₀ alkylthio group, the substituted C₃-C₁₀ cycloalkyl group,         the substituted C₁-C₁₀ heterocycloalkyl group, the substituted         C₃-C₁₀ cycloalkenyl group, the substituted C₂-C₁₀         heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the         substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀         arylthio group, the substituted C₁-C₆₀ heteroaryl group, the         substituted monovalent non-aromatic condensed polycyclic group,         and the substituted monovalent non-aromatic condensed         heteropolycyclic group may each independently be:     -   deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H,         —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino         group, an amidino group, a hydrazine group, a hydrazone group, a         carboxylic acid group or a salt thereof, a sulfonic acid group         or a salt thereof, a phosphoric acid group or a salt thereof, a         C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl         group, or a C₁-C₆₀ alkoxy group;     -   a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl         group, or a C₁-C₆₀ alkoxy group, each substituted with         deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H,         —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino         group, an amidino group, a hydrazine group, a hydrazone group, a         carboxylic acid group or a salt thereof, a sulfonic acid group         or a salt thereof, a phosphoric acid group or a salt thereof, a         C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, a monovalent non-aromatic condensed         heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Ge(Q₁₃)(Q₁₄)(Q₁₅),         —B(Q₁₆)(Q₁₇), —P(═O)(Q₁₈)(Q₁₉), —P(Q₁₈)(Q₁₉), or any combination         thereof;     -   a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, or a monovalent non-aromatic         condensed heteropolycyclic group, each unsubstituted or         substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H,         —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a         nitro group, an amino group, an amidino group, a hydrazine         group, a hydrazone group, a carboxylic acid group or a salt         thereof, a sulfonic acid group or a salt thereof, a phosphoric         acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀         alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a         C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, a monovalent non-aromatic condensed         heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Ge(Q₂₃)(Q₂₄)(Q₂₅),         —B(Q₂₆)(Q₂₇), —P(═O)(Q₂₈)(Q₂₉), —P(Q₂₈)(Q₂₉), or any combination         thereof;     -   —N(Q₃₁)(Q₃₂), —Ge(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), —P(═O)(Q₃₈)(Q₃₉)         or —P(Q₃₈)(Q₃₉); or any combination thereof,     -   Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ may each         independently be hydrogen; deuterium; —F; —Cl; —Br; —I; a         hydroxyl group; a cyano group; a nitro group; an amino group; an         amidino group; a hydrazine group; a hydrazone group; a         carboxylic acid group or a salt thereof; a sulfonic acid group         or a salt thereof; a phosphoric acid group or a salt thereof; a         C₁-C₆₀ alkyl group unsubstituted or substituted with deuterium,         a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group, or any combination         thereof; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a         C₁-C₆₀ alkoxy group; a C₃-C₁₀ cycloalkyl group; a C₁-C₁₀         heterocycloalkyl group; a C₃-C₁₀ cycloalkenyl group; a C₂-C₁₀         heterocycloalkenyl group; a C₆-C₆₀ aryl group unsubstituted or         substituted with deuterium, a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl         group, or any combination thereof; a C₆-C₆₀ aryloxy group; a         C₆-C₆₀ arylthio group; a C₁-C₆₀ heteroaryl group, a monovalent         non-aromatic condensed polycyclic group; or a monovalent         non-aromatic condensed heteropolycyclic group.

Another aspect of the present disclosure provides an organic light-emitting device including: a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode and including an emission layer, wherein the organic layer including at least one organometallic compound.

The organometallic compound may be included in the emission layer of the organic layer and the organometallic compound included in the emission layer may act as a dopant.

Another aspect of the present disclosure provides an electronic apparatus including the organic light-emitting device.

BRIEF DESCRIPTION OF THE DRAWING

These and/or other aspects will become apparent and more readily appreciated from the following description of the embodiments, taken in conjunction with FIGURE which is a schematic view of an organic light-emitting device according to an embodiment.

DETAILED DESCRIPTION

Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of the present description. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

It will be understood that when an element is referred to as being “on” another element, it can be directly on the other element or intervening elements may be present therebetween In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present

It will be understood that, although the terms “first,” “second,” “third” etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section Thus, “a first element,” “component,” “region,” “layer” or “section” discussed below could be termed a second element, component, region, layer or section without departing from the teachings herein.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, “a,” “an,” “the,” and “at least one” do not denote a limitation of quantity, and are intended to cover both the singular and plural, unless the context clearly indicates otherwise. For example, “an element” has the same meaning as “at least one element,” unless the context clearly indicates otherwise.

“Or” means “and/or.” As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items It will be further understood that the terms “comprises” and/or “comprising,” or “includes” and/or “including” when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or “top,” may be used herein to describe one element's relationship to another element as illustrated in the Figures It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the Figures For example, if the device in one of the figures is turned over, elements described as being on the “lower” side of other elements would then be oriented on “upper” sides of the other elements The exemplary term “lower,” can therefore, encompasses both an orientation of “lower” and “upper,” depending on the particular orientation of the FIGURE Similarly, if the device in one of the figures is turned over, elements described as “below” or “beneath” other elements would then be oriented “above” the other elements The exemplary terms “below” or “beneath” can, therefore, encompass both an orientation of above and below.

“About” or “approximately” as used herein is inclusive of the stated value and means within an acceptable range of deviation for the particular value as determined by one of ordinary skill in the art, considering the measurement in question and the error associated with measurement of the particular quantity (i.e., the limitations of the measurement system). For example, “about” can mean within one or more standard deviations, or within ±30%, 20%, 10% or 5% of the stated value.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Exemplary embodiments are described herein with reference to cross section illustrations that are schematic illustrations of idealized embodiments As such, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected Thus, embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, a region illustrated or described as flat may, typically, have rough and/or nonlinear features Moreover, sharp angles that are illustrated may be rounded Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the present claims.

An aspect of the present disclosure provides an organometallic compound represented by Formula 1 below:

M(L₁)_(n1)(L₂)_(n2).  Formula 1

M in Formula 1 may be a transition metal.

For example, M may be a first-row transition metal, a second-row transition metal, or a third-row transition metal, of the Periodic Table of Elements.

For example, M may be iridium (Ir), platinum (Pt), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), terbium (Tb), thulium (Tm), or rhodium (Rh).

In one or more embodiments, M may be Ir, Pt, Os, or Rh.

L₁ in Formula 1 may be a ligand represented by Formula 2A, and n1 in Formula 1 indicates the number of L₁(s) in Formula 1 and may be 1 or 2. When n1 is two, two L₁(s) may be identical to or different from each other.

L₂ in Formula 1 may be a ligand represented by Formula 2B, and n2 in Formula 1 indicates the number of L₂(s) in Formula 1 and may be 1 or 2. When n2 is two, two L₂(s) may be identical to or different from each other:

Formulae 2A and 2B will be understood by referring to a detailed description thereof to be provided later.

L₁ and L₂ in Formula 1 may be different from each other. That is, the organometallic compound represented by Formula 1 may be a heteroleptic complex.

In one or more embodiments, M may be Ir, and the sum of n1 and n2 may be 3; or M may be Pt, and the sum of n1 and n2 may be 2.

Y₁ and Y₄ in Formulae 2A and 2B may each independently be C or N.

For example, Y₁ in Formula 2A may be N and Y₄ in Formula 2B may be C.

X₁ in Formula 2B may be Si or Ge.

X₂₁ in Formula 2A may be O, S, S(═O), N(Z₂₉), C(Z₂₉)(Z₃₀), or Si(Z₂₉)(Z₃₀). Z₂₉ and Z₃₀ will be understood by referring to a detailed description thereof to be provided later.

For example, X₂₁ in Formula 2A may be O or S.

In Formula 2A, i) T₁ to T₄ may each independently be C, N, carbon linked to ring CY₁, or carbon linked to M in Formula 1, wherein one of T₁ to T₄ may be carbon linked to M in Formula 1, and one of the remaining T₁ to T₄ that are not linked to M in Formula 1 may be carbon linked to ring CY₁, and ii) T₅ to T₈ may each independently be C or N.

In Formula 1, when X₁ in Formula 2B is Si, at least one of the remaining T₁ to T₈ that are not carbon linked to M and ring CY₁ may be N.

In one or more embodiments, X₁ in Formula 2B may be Si, and at least one of the remaining T₁ to T₈ that are not carbon linked to M and ring CY₁ in Formula 2A may be N.

In one or more embodiments, X₁ in Formula 2B may be Ge, and T₁ to T₈ in Formula 2A may be C.

In one or more embodiments, X₁ in Formula 2B may be Ge, and at least one of the remaining T₁ to T₈ that are not carbon linked to M and ring CY₁ in Formula 2A may be N.

In one or more embodiments, T₈ in Formula 2A may be N.

Ring CY₁ and ring CY₁₄ in Formulae 2A and 2B may each independently be a C₅-C₃₀ carbocyclic group or a C₁-C₃₀ heterocyclic group.

For example, ring CY₁ and ring CY₁₄ may each independently be i) a first ring, ii) a second ring, iii) a condensed ring in which at least two first rings are condensed with each other, iv) a condensed ring in which at least two second rings are condensed with each other, or v) a condensed ring in which at least one first ring and at least one second ring are condensed with each other.

The first ring may be a cyclopentane group, a cyclopentadiene group, a furan group, a thiophene group, a pyrrole group, a silole group, an indene group, a benzofuran group, a benzothiophene group, an indole group, a benzosilole group, an oxazole group, an isoxazole group, an oxadiazole group, an isoxadiazole group, an oxatriazole group, an isoxatriazole group, a thiazole group, an isothiazole group, a thiadiazole group, an isothiadiazole group, a thiatriazole group, an isothiatriazole group, a pyrazole group, an imidazole group, a triazole group, a tetrazole group, an azasilole group, a diazasilole group, or a triazasilole group.

The second ring may be an admantane group, a norbornane group, a norbornene group, a cyclohexane group, a cyclohexene group, a benzene group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, or a triazine group.

In one or more embodiments, in Formulae 2A and 2B, ring CY₁ and ring CY₁₄ may each independently be a cyclopentane group, a cyclohexane group, a cycloheptane group, a cyclopentene group, a cyclohexene group, a cycloheptene group, a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a thiophene group, a furan group, an indole group, a benzoborole group, a benzophosphole group, an indene group, a benzosilole group, a benzogermole group, a benzothiophene group, a benzoselenophene group, a benzofuran group, a carbazole group, a dibenzoborole group, a dibenzophosphole group, a fluorene group, a dibenzosilole group, a dibenzogermole group, a dibenzothiophene group, a dibenzoselenophene group, a dibenzofuran group, a dibenzothiophene 5-oxide group, a 9H-fluorene-9-one group, a dibenzothiophene 5,5-dioxide group, an azaindole group, an azabenzoborole group, an azabenzophosphole group, an azaindene group, an azabenzosilole group, an azabenzogermole group, an azabenzothiophene group, an azabenzoselenophene group, an azabenzofuran group, an azacarbazole group, an azadibenzoborole group, an azadibenzophosphole group, an azafluorene group, an azadibenzosilole group, an azadibenzogermole group, an azadibenzothiophene group, an azadibenzoselenophene group, an azadibenzofuran group, an azadibenzothiophene 5-oxide group, an aza-9H-fluorene-9-one group, an azadibenzothiophene 5,5-dioxide group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, a 5,6,7,8-tetrahydroquinoline group, an admantane group, a norbornane group, or a norbornene group.

In one or more embodiments, ring CY₁ and ring CY₁₄ may each independently be a benzene group, a naphthalene group, 1,2,3,4-tetrahydronaphthalene group, a phenanthrene group, a pyridine group, a pyrimidine group, a pyrazine group, a triazine group, a benzofuran group, a benzothiophene group, a fluorene group, a carbazole group, a dibenzofuran group, a dibenzothiophene group, a dibenzosilole group, an azafluorene group, an azacarbazole group, an azadibenzofuran group, an azadibenzothiophene group, or an azadibenzosilole group.

In one or more embodiments, ring CY₁ in Formula 2A may be a pyridine group, a 5,6,7,8-tetrahydroisoquinoline group, or a 5,6,7,8-tetrahydroquinoline group.

In one or more embodiments, ring CY₁₄ in Formula 2B may be a benzene group, a naphthalene group, 1,2,3,4-tetrahydronaphthalene group, a dibenzothiophene group, a dibenzofuran group, or a pyridine group.

In Formula 2B, R₂₁ to R₂₃ may each independently be a C₁-C₆₀ alkyl group or a C₆-C₆₀ aryl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a phenyl group, or any combination thereof.

For example, R₂₁ to R₂₃ in Formula 2B may each independently be a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, a tert-decyl group, a phenyl group, a biphenyl group, or a naphthyl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a phenyl group, or any combination thereof.

In one or more embodiments, R₂₁ to R₂₃ may each independently be —CH₃, —CH₂CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CD₃, or —CD₂CH₃.

In one or more embodiments, R₂₁ to R₂₃ in Formula 2B may be identical to each other.

In one or more embodiments, at least two of R₂₁ to R₂₃ may be different from each other.

Z₁, Z₂, and R₁₁ to R₁₄ in Formulae 2A and 2B may each independently be hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₁-C₆₀ alkylthio group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁)(Q₂), —Ge(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), —P(═O)(Q₈)(Q₉) or —P(Q₈)(Q₉), and R₁₂ may be neither hydrogen nor a methyl group. Q₁ to Q₉ may be the same as described in this disclosure.

In Formulae 2A and 2B, a1 and b1 indicate the number of Z₁(s) and the number of R₁₄(s), respectively, and may each independently be an integer from 0 to 20. When a1 is two or more, two or more Z₁(s) may be identical to or different from each other, and when b1 is two or more, two or more R₁₄(s) may be identical to or different from each other. For example, a1 and b1 may each independently be an integer from 0 to 10.

In Formula 2A, a2 indicates the number of Z₂(s) and may each independently be an integer from 0 to 6. When a2 is two or more, two or more Z₂(s) may be identical to or different from each other. For example, a2 may each independently be 0, 1, 2 or 3.

In one or more embodiments, Z₁ in Formula 2A may be hydrogen, deuterium, —F, —Cl, —Br, —I, a cyano group, a substituted or unsubstituted C₁-C₆₀ alkyl group, or a substituted or unsubstituted C₃-C₁₀ cycloalkyl group.

In one or more embodiments, in Formula 2A,

-   -   Z₁ may be:     -   hydrogen, deuterium, —F, or a cyano group;     -   a C₁-C₂₀ alkyl group unsubstituted or substituted with         deuterium, —F, a cyano group, a C₃-C₁₀ cycloalkyl group, a         deuterated C₃-C₁₀ cycloalkyl group, a (C₁-C₂₀ alkyl)C₃-C₁₀         cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a deuterated         C₁-C₁₀ heterocycloalkyl group, a (C₁-C₂₀ alkyl)C₁-C₁₀         heterocycloalkyl group, or any combination thereof; or     -   a C₃-C₁₀ cycloalkyl group or a C₁-C₁₀ heterocycloalkyl group,         unsubstituted or substituted with deuterium, —F, a cyano group,         a C₁-C₂₀ alkyl group, a deuterated C₁-C₂₀ alkyl group, or any         combination thereof.

In one or more embodiments, in Formula 2A,

-   -   Z₁ may be:     -   hydrogen, deuterium, —F, or a cyano group;     -   a C₁-C₂₀ alkyl group unsubstituted or substituted with         deuterium, —F, a cyano group, a cyclopentyl group, a cyclohexyl         group, a cycloheptyl group, a cyclooctyl group, an adamantanyl         group, a norbornanyl group, a norbornenyl group, a         bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a         bicyclo[2.2.2]octyl group, a (C₁-C₂₀ alkyl)cyclopentyl group, a         (C₁-C₂₀ alkyl)cyclohexyl group, a (C₁-C₂₀ alkyl)cycloheptyl         group, a (C₁-C₂₀ alkyl)cyclooctyl group, a (C₁-C₂₀         alkyl)adamantanyl group, a (C₁-C₂₀ alkyl)norbornanyl group, a         (C₁-C₂₀ alkyl)norbornenyl group, a (C₁-C₂₀         alkyl)bicyclo[1.1.1]pentyl group, a (C₁-C₂₀         alkyl)bicyclo[2.1.1]hexyl group, a (C₁-C₂₀         alkyl)bicyclo[2.2.2]octyl group, or any combination thereof; or     -   a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclooctyl group, an adamantanyl group, a norbornanyl group, a         norbornenyl group, a bicyclo[1.1.1]pentyl group, a         bicyclo[2.1.1]hexyl group, or a bicyclo[2.2.2]octyl group, each         unsubstituted or substituted with deuterium, —F, a cyano group,         a C₁-C₂₀ alkyl group, or any combination thereof.

In one or more embodiments, Z₂ and R₁₁ to R₁₄ in Formulae 2A and 2B may each independently be:

-   -   hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amino group, an amidino group, a         hydrazine group, a hydrazone group, a carboxylic acid group or a         salt thereof, a sulfonic acid group or a salt thereof, a         phosphoric acid group or a salt thereof, —SF₅, C₁-C₂₀ alkyl         group, a C₁-C₂₀ alkoxy group or a C₁-C₂₀ alkylthio group;     -   a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group or a C₁-C₂₀         alkylthio group, each substituted with deuterium, —F, —Cl, —Br,         —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a         cyano group, a nitro group, an amino group, an amidino group, a         hydrazine group, a hydrazone group, a carboxylic acid group or a         salt thereof, a sulfonic acid group or a salt thereof, a         phosphoric acid group or a salt thereof, a C₁-C₁₀ alkyl group, a         cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclooctyl group, an adamantanyl group, a norbornanyl group, a         norbornenyl group, a cyclopentenyl group, a cyclohexenyl group,         a cycloheptenyl group, a bicyclo[1.1.1]pentyl group, a         bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, a         (C₁-C₂₀ alkyl)cyclopentyl group, a (C₁-C₂₀ alkyl)cyclohexyl         group, a (C₁-C₂₀ alkyl)cycloheptyl group, a (C₁-C₂₀         alkyl)cyclooctyl group, a (C₁-C₂₀ alkyl)adamantanyl group, a         (C₁-C₂₀ alkyl)norbornanyl group, a (C₁-C₂₀ alkyl)norbornenyl         group, a (C₁-C₂₀ alkyl)cyclopentenyl group, a (C₁-C₂₀         alkyl)cyclohexenyl group, a (C₁-C₂₀ alkyl)cycloheptenyl group, a         (C₁-C₂₀ alkyl)bicyclo[1.1.1]pentyl group, a (C₁-C₂₀         alkyl)bicyclo[2.1.1]hexyl group, a (C₁-C₂₀         alkyl)bicyclo[2.2.2]octyl group, a phenyl group, a (C₁-C₂₀         alkyl)phenyl group, a biphenyl group, a terphenyl group, a         naphthyl group, a pyridinyl group, a pyrimidinyl group, or any         combination thereof,     -   a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclooctyl group, an adamantanyl group, a norbornanyl group, a         norbornenyl group, a cyclopentenyl group, a cyclohexenyl group,         a cycloheptenyl group, a bicyclo[1.1.1]pentyl group, a         bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, a phenyl         group, a (C₁-C₂₀ alkyl)phenyl group, a biphenyl group, a         terphenyl group, a naphthyl group, a fluorenyl group, a         phenanthrenyl group, an anthracenyl group, a fluoranthenyl         group, a triphenylenyl group, a pyrenyl group, a chrysenyl         group, a pyrrolyl group, a thiophenyl group, a furanyl group, an         imidazolyl group, a pyrazolyl group, a thiazolyl group, an         isothiazolyl group, an oxazolyl group, an isoxazolyl group, a         pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a         pyridazinyl group, an isoindolyl group, an indolyl group, an         indazolyl group, a purinyl group, a quinolinyl group, an         isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl         group, a quinazolinyl group, a cinnolinyl group, a carbazolyl         group, a phenanthrolinyl group, a benzimidazolyl group, a         benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl         group, a benzoxazolyl group, a benzoisoxazolyl group, a         triazolyl group, a tetrazolyl group, an oxadiazolyl group, a         triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl         group, a benzocarbazolyl group, a dibenzocarbazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, an         azacarbazolyl group, an azadibenzofuranyl group, or an         azadibenzothiophenyl group, each unsubstituted or substituted         with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃,         —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an         amino group, an amidino group, a hydrazine group, a hydrazone         group, a carboxylic acid group or a salt thereof, a sulfonic         acid group or a salt thereof, a phosphoric acid group or a salt         thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclooctyl group, an adamantanyl group, a norbornanyl group, a         norbornenyl group, a cyclopentenyl group, a cyclohexenyl group,         a cycloheptenyl group, a bicyclo[1.1.1]pentyl group, a         bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, a         (C₁-C₂₀ alkyl)cyclopentyl group, a (C₁-C₂₀ alkyl)cyclohexyl         group, a (C₁-C₂₀ alkyl)cycloheptyl group, a (C₁-C₂₀         alkyl)cyclooctyl group, a (C₁-C₂₀ alkyl)adamantanyl group, a         (C₁-C₂₀ alkyl)norbornanyl group, a (C₁-C₂₀ alkyl)norbornenyl         group, a (C₁-C₂₀ alkyl)cyclopentenyl group, a (C₁-C₂₀         alkyl)cyclohexenyl group, a (C₁-C₂₀ alkyl)cycloheptenyl group, a         (C₁-C₂₀ alkyl)bicyclo[1.1.1]pentyl group, a (C₁-C₂₀         alkyl)bicyclo[2.1.1]hexyl group, a (C₁-C₂₀         alkyl)bicyclo[2.2.2]octyl group, a phenyl group, a (C₁-C₂₀         alkyl)phenyl group, a biphenyl group, a terphenyl group, a         naphthyl group, a fluorenyl group, a phenanthrenyl group, an         anthracenyl group, a fluoranthenyl group, a triphenylenyl group,         a pyrenyl group, a chrysenyl group, a pyrrolyl group, a         thiophenyl group, a furanyl group, an imidazolyl group, a         pyrazolyl group, a thiazolyl group, an isothiazolyl group, an         oxazolyl group, an isoxazolyl group, a pyridinyl group, a         pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an         isoindolyl group, an indolyl group, an indazolyl group, a         purinyl group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl         group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl         group, a benzimidazolyl group, a benzofuranyl group, a         benzothiophenyl group, a benzoisothiazolyl group, a benzoxazolyl         group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl         group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, an imidazopyridinyl group, an         imidazopyrimidinyl group, an azacarbazolyl group, an         azadibenzofuranyl group, an azadibenzothiophenyl group, or any         combination thereof; or     -   —N(Q₁)(Q₂), —Ge(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), —P(═O)(Q₈)(Q₉), or         —P(Q₈)(Q₉),     -   R₁₂ may not be hydrogen nor a methyl group, and

Q₁ to Q₉ may each independently be:

-   -   —CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂,         —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, or         —CD₂CDH₂; or     -   an n-propyl group, an isopropyl group, an n-butyl group, a         sec-butyl group, an isobutyl group, a tert-butyl group, an         n-pentyl group, a tert-pentyl group, a neopentyl group, an         isopentyl group, a sec-pentyl group, a 3-pentyl group, a         sec-isopentyl group, a phenyl group, a biphenyl group, or a         naphthyl group, each unsubstituted or substituted with         deuterium, a C₁-C₁₀ alkyl group, a phenyl group, or any         combination thereof.

In one or more embodiments, a number of carbon included in R₁₂ of Formula 2B may be at least two.

In one or more embodiments, R₁₂ in Formula 2B may be:

-   -   a C₂-C₂₀ alkyl group or a C₂-C₂₀ alkoxy group;     -   a methyl group or a methoxy group, each substituted with a         C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a         C₆-C₁₄ aryl group, a C₁-C₁₄ heteroaryl group, a monovalent         non-aromatic condensed polycyclic group, a monovalent         non-aromatic condensed heteropolycyclic group, or any         combination thereof;     -   a C₂-C₂₀ alkyl group or a C₂-C₂₀ alkoxy group, each substituted         with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃,         —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an         amino group, an amidino group, a hydrazine group, a hydrazone         group, a carboxylic acid group or a salt thereof, a sulfonic         acid group or a salt thereof, a phosphoric acid group or a salt         thereof, a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a C₃-C₁₀         cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀         cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₁₄         aryl group, a C₁-C₁₄ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, a monovalent non-aromatic condensed         heteropolycyclic group, or any combination thereof;     -   a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a         C₆-C₁₄ aryl group, a C₁-C₁₄ heteroaryl group, a monovalent         non-aromatic condensed polycyclic group, or a monovalent         non-aromatic condensed heteropolycyclic group, each         unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I,         —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a         cyano group, a nitro group, an amino group, an amidino group, a         hydrazine group, a hydrazone group, a carboxylic acid group or a         salt thereof, a sulfonic acid group or a salt thereof, a         phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a         C₁-C₂₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀         heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀         heterocycloalkenyl group, a C₆-C₁₄ aryl group, a C₁-C₁₄         heteroaryl group, a monovalent non-aromatic condensed polycyclic         group, a monovalent non-aromatic condensed heteropolycyclic         group, or any combination thereof; or     -   —N(Q₁)(Q₂), —Ge(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), or —P(═O)(Q₈)(Q₉).

In one or more embodiments, R₁₂ in Formula 2B may be:

-   -   a methyl group or a methoxy group, each substituted with a         cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclooctyl group, an adamantanyl group, a norbornanyl group, a         norbornenyl group, a cyclopentenyl group, a cyclohexenyl group,         a cycloheptenyl group, a bicyclo[1.1.1]pentyl group, a         bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, a         (C₁-C₂₀ alkyl)cyclopentyl group, a (C₁-C₂₀ alkyl)cyclohexyl         group, a (C₁-C₂₀ alkyl)cycloheptyl group, a (C₁-C₂₀         alkyl)cyclooctyl group, a (C₁-C₂₀ alkyl)adamantanyl group, a         (C₁-C₂₀ alkyl)norbornanyl group, a (C₁-C₂₀ alkyl)norbornenyl         group, a (C₁-C₂₀ alkyl)cyclopentenyl group, a (C₁-C₂₀         alkyl)cyclohexenyl group, a (C₁-C₂₀ alkyl)cycloheptenyl group, a         (C₁-C₂₀ alkyl)bicyclo[1.1.1]pentyl group, a (C₁-C₂₀         alkyl)bicyclo[2.1.1]hexyl group, a (C₁-C₂₀         alkyl)bicyclo[2.2.2]octyl group, a phenyl group, a (C₁-C₂₀         alkyl)phenyl group, a naphthyl group, a pyridinyl group, a         pyrimidinyl group, or any combination thereof;     -   a methyl group or a methoxy group, each substituted with i)         cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclooctyl group, an adamantanyl group, a norbornanyl group, a         norbornenyl group, a cyclopentenyl group, a cyclohexenyl group,         a cycloheptenyl group, a bicyclo[1.1.1]pentyl group, a         bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, a         (C₁-C₂₀ alkyl)cyclopentyl group, a (C₁-C₂₀ alkyl)cyclohexyl         group, a (C₁-C₂₀ alkyl)cycloheptyl group, a (C₁-C₂₀         alkyl)cyclooctyl group, a (C₁-C₂₀ alkyl)adamantanyl group, a         (C₁-C₂₀ alkyl)norbornanyl group, a (C₁-C₂₀ alkyl)norbornenyl         group, a (C₁-C₂₀ alkyl)cyclopentenyl group, a (C₁-C₂₀         alkyl)cyclohexenyl group, a (C₁-C₂₀ alkyl)cycloheptenyl group, a         (C₁-C₂₀ alkyl)bicyclo[1.1.1]pentyl group, a (C₁-C₂₀         alkyl)bicyclo[2.1.1]hexyl group, a (C₁-C₂₀         alkyl)bicyclo[2.2.2]octyl group, a phenyl group, a (C₁-C₂₀         alkyl)phenyl group, a naphthyl group, a pyridinyl group, a         pyrimidinyl group, or any combination thereof, and ii) at least         one deuterium;     -   a C₂-C₂₀ alkyl group or a C₂-C₂₀ alkoxy group, each         unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I,         —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a         cyano group, a nitro group, an amino group, an amidino group, a         hydrazine group, a hydrazone group, a carboxylic acid group or a         salt thereof, a sulfonic acid group or a salt thereof, a         phosphoric acid group or a salt thereof, a C₁-C₂₀ alkyl group, a         cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclooctyl group, an adamantanyl group, a norbornanyl group, a         norbornenyl group, a cyclopentenyl group, a cyclohexenyl group,         a cycloheptenyl group, a bicyclo[1.1.1]pentyl group, a         bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, a         (C₁-C₂₀ alkyl)cyclopentyl group, a (C₁-C₂₀ alkyl)cyclohexyl         group, a (C₁-C₂₀ alkyl)cycloheptyl group, a (C₁-C₂₀         alkyl)cyclooctyl group, a (C₁-C₂₀ alkyl)adamantanyl group, a         (C₁-C₂₀ alkyl)norbornanyl group, a (C₁-C₂₀ alkyl)norbornenyl         group, a (C₁-C₂₀ alkyl)cyclopentenyl group, a (C₁-C₂₀         alkyl)cyclohexenyl group, a (C₁-C₂₀ alkyl)cycloheptenyl group, a         (C₁-C₂₀ alkyl)bicyclo[1.1.1]pentyl group, a (C₁-C₂₀         alkyl)bicyclo[2.1.1]hexyl group, a (C₁-C₂₀         alkyl)bicyclo[2.2.2]octyl group, a phenyl group, a (C₁-C₂₀         alkyl)phenyl group, a naphthyl group, a pyridinyl group, a         pyrimidinyl group, or any combination thereof; or     -   a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclooctyl group, an adamantanyl group, a norbornanyl group, a         norbornenyl group, a cyclopentenyl group, a cyclohexenyl group,         a cycloheptenyl group, a bicyclo[1.1.1]pentyl group, a         bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, a phenyl         group, a (C₁-C₂₀ alkyl)phenyl group, a biphenyl group, a         terphenyl group, a naphthyl group, a fluorenyl group, a         phenanthrenyl group, an anthracenyl group, a fluoranthenyl         group, a triphenylenyl group, a pyrenyl group, a chrysenyl         group, a pyrrolyl group, a thiophenyl group, a furanyl group, an         imidazolyl group, a pyrazolyl group, a thiazolyl group, an         isothiazolyl group, an oxazolyl group, an isoxazolyl group, a         pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a         pyridazinyl group, an isoindolyl group, an indolyl group, an         indazolyl group, a purinyl group, a quinolinyl group, an         isoquinolinyl group, a benzoquinolinyl group, a quinoxalinyl         group, a quinazolinyl group, a cinnolinyl group, a carbazolyl         group, a phenanthrolinyl group, a benzimidazolyl group, a         benzofuranyl group, a benzothiophenyl group, a benzoisothiazolyl         group, a benzoxazolyl group, a benzoisoxazolyl group, a         triazolyl group, a tetrazolyl group, an oxadiazolyl group, a         triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl         group, a benzocarbazolyl group, a dibenzocarbazolyl group, an         imidazopyridinyl group, an imidazopyrimidinyl group, an         azacarbazolyl group, an azadibenzofuranyl group, or an         azadibenzothiophenyl group, each unsubstituted or substituted         with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃,         —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an         amino group, an amidino group, a hydrazine group, a hydrazone         group, a carboxylic acid group or a salt thereof, a sulfonic         acid group or a salt thereof, a phosphoric acid group or a salt         thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a         cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a         cyclooctyl group, an adamantanyl group, a norbornanyl group, a         norbornenyl group, a cyclopentenyl group, a cyclohexenyl group,         a cycloheptenyl group, a bicyclo[1.1.1]pentyl group, a         bicyclo[2.1.1]hexyl group, a bicyclo[2.2.2]octyl group, a         (C₁-C₂₀ alkyl)cyclopentyl group, a (C₁-C₂₀ alkyl)cyclohexyl         group, a (C₁-C₂₀ alkyl)cycloheptyl group, a (C₁-C₂₀         alkyl)cyclooctyl group, a (C₁-C₂₀ alkyl)adamantanyl group, a         (C₁-C₂₀ alkyl)norbornanyl group, a (C₁-C₂₀ alkyl)norbornenyl         group, a (C₁-C₂₀ alkyl)cyclopentenyl group, a (C₁-C₂₀         alkyl)cyclohexenyl group, a (C₁-C₂₀ alkyl)cycloheptenyl group, a         (C₁-C₂₀ alkyl)bicyclo[1.1.1]pentyl group, a (C₁-C₂₀         alkyl)bicyclo[2.1.1]hexyl group, a (C₁-C₂₀         alkyl)bicyclo[2.2.2]octyl group, a phenyl group, a (C₁-C₂₀         alkyl)phenyl group, a biphenyl group, a terphenyl group, a         naphthyl group, a fluorenyl group, a phenanthrenyl group, an         anthracenyl group, a fluoranthenyl group, a triphenylenyl group,         a pyrenyl group, a chrysenyl group, a pyrrolyl group, a         thiophenyl group, a furanyl group, an imidazolyl group, a         pyrazolyl group, a thiazolyl group, an isothiazolyl group, an         oxazolyl group, an isoxazolyl group, a pyridinyl group, a         pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, an         isoindolyl group, an indolyl group, an indazolyl group, a         purinyl group, a quinolinyl group, an isoquinolinyl group, a         benzoquinolinyl group, a quinoxalinyl group, a quinazolinyl         group, a cinnolinyl group, a carbazolyl group, a phenanthrolinyl         group, a benzimidazolyl group, a benzofuranyl group, a         benzothiophenyl group, a benzoisothiazolyl group, a benzoxazolyl         group, a benzoisoxazolyl group, a triazolyl group, a tetrazolyl         group, an oxadiazolyl group, a triazinyl group, a dibenzofuranyl         group, a dibenzothiophenyl group, a benzocarbazolyl group, a         dibenzocarbazolyl group, an imidazopyridinyl group, an         imidazopyrimidinyl group, an azacarbazolyl group, an         azadibenzofuranyl group, an azadibenzothiophenyl group, or any         combination thereof.

In one or more embodiments, the organometallic compound represented by Formula 1 may satisfy at least one of Condition (1) to Condition (3) below:

Condition (1)

In Formula 2A, Z₁ is not hydrogen, and a1 is an integer of 1 to 20.

Condition (2)

In Formula 2B, R₁₄ is not hydrogen, and b1 is an integer of 1 to 20.

Condition (3)

In Formula 2A, Z₂ is not hydrogen, and a2 is an integer of 1 to 6.

In one or more embodiments, the organometallic compound represented by Formula 1 may include at least one deuterium, at least one fluoro group (—F), at least one cyano group (—CN), or any combination thereof.

In one or more embodiments, the organometallic compound represented by Formula 1 may include at least one deuterium.

In one or more embodiments, the organometallic compound represented by Formula 1 may satisfy at least one of Condition A to Condition I below:

Condition A

In Formula 2A, Z₁ is not hydrogen, a1 is an integer of 1 to 20, and at least one of Z₁(s) in the number of a1 includes deuterium.

Condition B

In Formula 2A, Z₂ is not hydrogen, a2 is an integer of 1 to 6, and at least one of Z₂(s) in the number of a2 includes deuterium.

Condition C

In Formula 2A, Z₂ is not hydrogen, a2 is an integer of 1 to 6, and at least one of Z₂(s) in the number of a2 includes —F.

Condition D

In Formula 2A, Z₂ is not hydrogen, a2 is an integer of 1 to 6, and at least one of Z₂(s) in the number of a2 includes —CN.

Condition E

In Formula 2A, Z₂ is not hydrogen, a2 is an integer of 1 to 6, and at least one of Z₂(s) in the number of a2 is a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.

Condition F

In Formula 2B, at least one of R₂₁ to R₂₃ includes deuterium.

Condition G

In Formula 2B, R₁₂ includes deuterium.

Condition H

In Formula 2B, R₁₄ is not hydrogen, b1 is an integer of 1 to 20, and at least one of R₁₄(s) in the number of b1 includes deuterium.

Condition I

In Formula 2B, R₁₄ is not hydrogen, b1 is an integer of 1 to 20, and at least one of R₁₄(s) in the number of b1 includes —F.

In one or more embodiments, Z₂ in Formula 2A may not be hydrogen, a2 may be an integer from 1 to 3, and at least one of Z₂(s) in number of a2 may each independently be a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₁-C₆₀ alkylthio group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.

In one or more embodiments, Z₂ in Formula 2A may not be hydrogen, a2 may be an integer from 1 to 3, and at least one of Z₂(s) in number of a2 may each independently be a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.

In one or more embodiments, Z₁ in Formula 2A may be hydrogen, deuterium, —F, a cyano group, a nitro group, —SF₅, —CH₃, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, —OCH₃, —OCDH₂, —OCD₂H, —OCD₃, —SCH₃, —SCDH₂, —SCD₂H, —SCD₃, one of groups represented by Formulae 9-1 to 9-39, one of groups represented by Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with deuterium, one of groups represented by Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with —F, one of groups represented by Formulae 9-201 to 9-233, one of groups represented by Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with deuterium, one of groups represented by Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with —F, one of groups represented by Formulae 10-1 to 10-11, one of groups represented by Formulae 10-1 to 10-11 in which at least one hydrogen is substituted with deuterium, or one of groups represented by Formulae 10-1 to 10-11 in which at least one hydrogen is substituted with —F.

In one or more embodiments, Z₂ and R₁₁ to R₁₄ in Formulae 2A and 2B may each independently be hydrogen, deuterium, —F, a cyano group, a nitro group, —SF₅, —CH₃, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, —OCH₃, —OCDH₂, —OCD₂H, —OCD₃, —SCH₃, —SCDH₂, —SCD₂H, —SCD₃, one of groups represented by Formulae 9-1 to 9-39, one of groups represented by Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with deuterium, one of groups represented by Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with —F, one of groups represented by Formulae 9-201 to 9-233, one of groups represented by Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with deuterium, one of groups represented by Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with —F, one of groups represented by Formulae 10-1 to 10-132, one of groups represented by Formulae 10-1 to 10-132 in which at least one hydrogen is substituted with deuterium, or one of groups represented by Formulae 10-1 to 10-132 in which at least one hydrogen is substituted with —F, one of groups represented by Formulae 10-201 to 10-353, one of groups represented by Formulae 10-201 to 10-353 in which at least one hydrogen is substituted with deuterium, one of groups represented by Formulae 10-201 to 10-353 in which at least one hydrogen is substituted with —F, —N(Q₁)(Q₂), or —Ge(Q₃)(Q₄)(Q₅) (wherein Q₁ to Q₅ are the same as described above).

In one or more embodiments, R₁₂ in Formula 2B may be one of groups represented by Formulae 9-1 to 9-39, one of groups represented by Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with deuterium, one of groups represented by Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with —F, one of groups represented by Formulae 9-201 to 9-233, one of groups represented by Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with deuterium, one of groups represented by Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with —F, one of groups represented by Formulae 10-1 to 10-132, one of groups represented by Formulae 10-1 to 10-132 in which at least one hydrogen is substituted with deuterium, or one of groups represented by Formulae 10-1 to 10-132 in which at least one hydrogen is substituted with —F, one of groups represented by Formulae 10-201 to 10-353, one of groups represented by Formulae 10-201 to 10-353 in which at least one hydrogen is substituted with deuterium, or one of groups represented by Formulae 10-201 to 10-353 in which at least one hydrogen is substituted with —F:

In Formulae 9-1 to 9-39, 9-201 to 9-233, 10-1 to 10-132 and 10-201 to 10-353,

-   -   * indicates a binding site to a neighboring atom,     -   Ph indicates a phenyl group,     -   TMS indicates a trimethylsilyl group,     -   TMG indicates a trimethylgermyl group, and     -   OMe indicates a methoxy group.

The term “groups represented by Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with deuterium” and “groups represented by Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with deuterium” as used herein may be, for example, groups represented by Formulae 9-501 to 9-514 and 9-601 to 9-635:

The term “groups represented by Formulae 9-1 to 9-39 in which at least one hydrogen is substituted with —F” and “groups represented by Formulae 9-201 to 9-233 in which at least one hydrogen is substituted with —F” as used herein may be, for example, groups represented by Formulae 9-701 to 9-710:

The term “groups represented by Formulae 10-1 to 10-132 in which at least one hydrogen is substituted with deuterium” and “groups represented by Formulae 10-201 to 10-353 in which at least one hydrogen is substituted with deuterium” as used herein may be, for example, groups represented by Formulae 10-501 to 10-553:

The term “groups represented by Formulae 10-1 to 10-132 in which at least one hydrogen is substituted with —F” and “groups represented by Formulae 10-201 to 10-353 in which at least one hydrogen is substituted with —F” as used herein may be, for example, groups represented by Formulae 10-601 to 10-620:

In Formulae 2A and 2B, i) two or more of R₂₁ to R₂₃ may optionally be linked to form a C₅-C₃₀ carbocyclic group that is unsubstituted or substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic group that is unsubstituted or substituted with at least one R_(10a), ii) two or more of a plurality of Z₁(s) may optionally be linked to form a C₅-C₃₀ carbocyclic group that is unsubstituted or substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic group that is unsubstituted or substituted with at least one R_(10a), iii) two or more of a plurality of Z₂(s) may optionally be linked to form a C₅-C₃₀ carbocyclic group that is unsubstituted or substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic group that is unsubstituted or substituted with at least one R_(10a), iv) R₁₂ and R₁₃ may optionally be linked to form a C₅-C₃₀ carbocyclic group that is unsubstituted or substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic group that is unsubstituted or substituted with at least one R_(10a), v) two or more of a plurality of R₁₄(s) may optionally be linked to form a C₅-C₃₀ carbocyclic group that is unsubstituted or substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic group that is unsubstituted or substituted with at least one R_(10a), and vi) two or more of Z₁, Z₂ and R₁₁ to R₁₄ may optionally be linked to form a C₅-C₃₀carbocyclic group that is unsubstituted or substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic group that is unsubstituted or substituted with at least one R_(10a).

R_(10a) may be the same as defined in connection with R₁₄ in the present specification.

In Formulae 2A and 2B, * and *′ each indicate a binding site to M in Formula 1.

In one or more embodiments, the group represented by

in Formula 2A may be a group represented by one of Formulae CY1-1 to CY1-28:

In Formulae CY1-1 to CY1-28,

-   -   Z₁₁ to Z₁₄ may each be the same as defined in connection with         Z₁, provided that each of Z₁₁ to Z₁₄ are not hydrogen,     -   ring CY_(10a) may be a C₅-C₃₀ carbocyclic group or a C₁-C₃₀         heterocyclic group,     -   R_(10a) may be the same as described above,     -   aa may be an integer from 0 to 10,     -   * indicates a binding site to M in Formula 1, and     -   *′ indicates a binding site to one of T₁ to T₄ in Formula 2A.

In one or more embodiments, the group represented by

in Formula 2A may be a group represented by one of Formulae CY1-4, CY1-7, CY1-9, CY1-11, CY1-12, and CY1-14 to CY1-24.

In one or more embodiments, the group represented by

in Formula 2A may be a group represented by one of Formulae CY2-1 to CY2-6:

In Formulae CY2-1 to CY2-6,

-   -   T₁ to T₈ may each independently be C or N,     -   X₂₁ may be the same as described above,     -   *″ indicates a binding site to ring CY₁ in Formula 2A, and     -   *′ indicates a binding site to M in Formula 1.

For example,

-   -   a) X₁ in Formula 2B may be Ge, and each of T₁ to T₈ in Formulae         CY2-1 to CY2-6 may be C, (and/or)     -   b) X₁ in Formula 2B may be Si or Ge, and at least one of T₃ to         T₈ (for example, one or two of T₃ to T₈) in Formulae CY2-1 and         CY2-6 may be N, (and/or)     -   c) X₁ in Formula 2B may be Si or Ge, and at least one of T₁, T₂,         and T₅ to T₈ (for example, one or two of T₁, T₂, and T₅ to T₈)         in Formulae CY2-2 and CY2-5 may be N, (and/or)     -   d) X₁ in Formula 2B may be Si or Ge, and at least one of T₁ and         T₄ to T₈ (for example, one or two T₁ and T₄ to T₈) in Formulae         CY2-3 and CY2-4 may be N.

In one or more embodiments,

-   -   1) T₁ to T₈ in Formulae CY2-1 to CY2-6 may be C;     -   2) one of T₃ to T₈ in Formula CY2-1 may be N, and the remaining         T₃ to T₈ that are not N in Formula CY2-1 may be C;     -   3) T₃ and T₈ in Formula CY2-1 may be N, and T₄ to T₇ in Formula         CY2-1 may be C;     -   4) T₅ and T₈ in Formula CY2-1 may be N, and T₃ to T₈ and T₇ in         Formula CY2-1 may be C;     -   5) one of T₁, T₂ and T₈ in Formula CY2-2 may be N, and the         remaining T₁, T₂ and T₅ to T₈ that are not N in Formula CY2-2         may be C;     -   6) T₁ and T₈ in Formula CY2-2 may be N, and T₂ and T₅ to T₇ in         Formula CY2-2 may be C;     -   7) T₂ and T₈ in Formula CY2-2 may be N, and T₁ and T₅ to T₇ in         Formula CY2-2 may be C;     -   8) one of T₁, T₄ and T₈ in Formulae CY2-3 and CY2-4 may be N,         and the remaining T₁, T₄ and T₅ to T₈ that are not N in Formulae         CY2-3 and CY2-4 may be C;     -   9) T₁ and T₈ in Formulae CY2-3 and CY2-4 may be N, and T₄ and T₅         to T₇ in Formulae CY2-3 and CY2-4 may be C;     -   10) T₄ and T₈ in Formulae CY2-3 and CY2-4 may be N, and T₁ and         T₅ to T₇ in Formulae CY2-3 and CY2-4 may be C;     -   11) one of T₁ and T₈ in Formula CY2-5 may be N, and the         remaining T₁, T₂ and T₅ to T₈ that are not N in Formula CY2-5         may be C;     -   12) T₁ and T₈ in Formula CY2-5 may be N, and T₂ and T₅ to T₇ in         Formula CY2-5 may be C;     -   13) one of T₄ and T₈ in Formula CY2-6 may be N, and the         remaining T₃ to T₈ that are not N in Formula CY2-6 may be C; or     -   14) T₄ and T₈ in Formula CY2-6 may be N, and T₃ and T₅ to T₇ in         Formula CY2-6 may be C.

In one or more embodiments, a group represented by

in Formula 2A may be a group represented by one of Formulae CY2-1001 to CY2-1141, CY2-2001 to CY2-2092, CY2-3001 to CY2-3092, CY2-4001 to CY2-4092, CY2-5001 to CY2-5065 and CY2-6001 to CY2-6065:

In Formulae CY2-1001 to CY2-1141, CY2-2001 to CY2-2092, CY2-3001 to CY2-3092, CY2-4001 to CY2-4092, CY2-5001 to CY2-5065 and CY2-6001 to CY2-6065,

-   -   X₂₁ may each be the same as described above,     -   Z₂₁ to Z₂₈ may each be the same as defined in connection with         Z₂, provided that each of Z₂₁ to Z₂₈ are not hydrogen,     -   *″ indicates a binding site to ring CY₁ in Formula 2A, and     -   *′ indicates a binding site to M in Formula 1.

In one or more embodiments, a group represented by

in Formula 2B may be a group represented by one of Formulae CY14-1 to CY14-64:

In Formulae CY14-1 to CY14-64,

-   -   R₁₄ may be the same as described above,     -   X₁₄ may be C(R₁)(R₂), N(R₁), O, S, or Si(R₁)(R₂),     -   R₁ to R₈ may each be the same as defined in connection with R₁₄         in the present specification,     -   b18 may be an integer from 0 to 8,     -   b16 may be an integer from 0 to 6,     -   b15 may be an integer from 0 to 5,     -   b14 may be an integer from 0 to 4,     -   b13 may be an integer from 0 to 3,     -   b12 may be an integer from 0 to 2,     -   *″ indicates a binding site to a carbon atom of a neighboring         pyridine ring in Formula 2B, and     -   *′ indicates a binding site to M in Formula 1.

In one or more embodiments, a group represented by

in Formula 2B may be a group represented by one of Formulae CY14(1) to CY14(63):

In Formulae CY14(1) to CY14(63),

-   -   R_(14a) to R_(14d) may each the same as defined in connection         with R₁₄, wherein each of R_(14a) to R_(14d) may not be         hydrogen,     -   X₁₄ may be C(R₁)(R₂), N(R₁), O, S or Si(R₁)(R₂),     -   R₁ to R₈ may each the same as defined in connection with R₁₄,         wherein     -   *″ indicates a binding site to a carbon atom of a neighboring         pyridine ring in Formula 2B, and     -   *′ indicates a binding site to M in Formula 1.

In one or more embodiments, the organometallic compound may be represented by Formula 1A:

In Formula 1A,

-   -   M, n1, n2, X₁, X₂₁, R₂₁ to R₂₃, and R₁ to R₁₃ may each be the         same as described above,     -   T₁₁ may be N or C(Z₁₁), T₁₂ may be N or C(Z₁₂), T₁₃ may be N or         C(Z₁₃), and T₁₄ may be N or C(Z₁₄), wherein Z₁₁ to Z₁₄ may each         be the same as defined in connection with Z₁,     -   T₂₁ may be N, C(Z₂₁), carbon linked to a neighboring 6-membered         ring, or carbon linked to M in Formula 1, T₂₂ may be N, C(Z₂₂),         carbon linked to a neighboring 6-membered ring, or carbon linked         to M in Formula 1, T₂₃ may be N, C(Z₂₃), carbon linked to a         neighboring 6-membered ring, or carbon linked to M in Formula 1,         T₂₄ may be N, C(Z₂₄), carbon linked to a neighboring 6-membered         ring, or carbon linked to M in Formula 1, T₂₅ may be N or         C(Z₂₅), T₂₆ may be N or C(Z₂₆), T₂₇ may be N or C(Z₂₇), and T₂₈         may be N or C(Z₂₈), wherein one of T₂₁ to T₂₄ may be carbon         linked to M in Formula 1, one of the remaining T₂₁ to T₂₄ that         are not linked to M in Formula 1 may be carbon linked to a         neighboring 6-membered ring, and Z₂₁ to Z₂₄ may each be the same         as defined in connection with Z₂,     -   T₃₁ may be N or C(R_(14a)), T₃₂ may be N or C(R_(14b)), T₃₃ may         be N or C(R_(14c)), and T₂₄ may be N or C(R_(14a)), wherein         R_(14a) to R_(14d) may each be the same as defined in connection         with R₁₄,     -   two or more of Z₁ to Z₁₄ may optionally be linked to form a         C₅-C₃₀ carbocyclic group that is unsubstituted or substituted         with at least one R_(10a) or a C₁-C₃₀ heterocyclic group that is         unsubstituted or substituted with at least one R_(10a),     -   two or more of Z₂₁ to Z₂₈ may optionally be linked to form a         C₅-C₃₀ carbocyclic group that is unsubstituted or substituted         with at least one R_(10a) or a C₁-C₃₀ heterocyclic group that is         unsubstituted or substituted with at least one R_(10a),     -   R₁₂ and R₁₃ may optionally be linked to form a C₅-C₃₀         carbocyclic group that is unsubstituted or substituted with at         least one R_(10a) or a C₁-C₃₀ heterocyclic group that is         unsubstituted or substituted with at least one R_(10a),     -   two or more of R_(14a) to R_(14d) may optionally be linked to         form a C₅-C₃₀carbocyclic group that is unsubstituted or         substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic         group that is unsubstituted or substituted with at least one         R_(10a), and     -   R_(10a) may be the same as defined in connection with R₁₄.

Descriptions for Formula 1A may refer to descriptions for Formula 1 in this disclosure.

For example, T₁₃ in Formula 1A may be C(Z₁₃) and Z₁₃ may not be a hydrogen.

In one or more embodiments, the number of silicon (Si) atoms in the organometallic compound represented by Formula 1 may be 1 or 2.

In one or more embodiments, the organometallic compound may be one of Compounds 1 to 1620:

In Compounds 1 to 1620, OMe indicates a methoxy group.

L₁ of the organometallic compound represented by Formula 1 may be a ligand represented by Formula 2A, and n1 which indicates the number of L₁(s) may be 1 or 2. L₂ of the organometallic compound represented by Formula 1 may be a ligand represented by Formula 2B, and n2 which indicates the number of L₂(s) may be 1 or 2. Here, L₁ and L₂ are different from each other. That is, the organometallic compound may be a heteroleptic complex essentially including, as ligands linked to metal M, at least one ligand represented by Formula 2A and at least one ligand represented by Formula 2B.

A group represented by *—X₁(R₂₁)(R₂₂)(R₂₃) in Formula 1 may be linked to the fifth position of a pyridine ring in a ligand represented by Formula 2B (see Formula 2B). Accordingly, the organometallic compound including the ligand represented by Formula 2B may have excellent heat resistance and degradation resistance so that an electronic device, for example, an organic light-emitting device, including the organometallic compound may have high stability and long lifespan in production, storage, and/or operation.

Furthermore, when X₁ is Si, at least one of T₁ to T₈ which are not linked to M and ring CY₁ in Formula 2A may be N. Accordingly, an electronic device, for example, an organic light-emitting device, including the organometallic compound represented by Formula 1 may have improved driving voltage and roll-off ratio.

In one or more embodiments, in Formulae 2A and 2B, R₂₁ to R₂₃, Z₁, Z₂, and R₁ to R₁₄ do not each include a silicon (Si). Accordingly, an electronic device, for example, an organic light-emitting device, including the organometallic compound represented by Formula 1 may have improved out-coupling characteristics.

In addition, R₁₂ in Formula 2B is not hydrogen nor a methyl group. As such, the organometallic compound represented by Formula 1 may emit light that is shifted toward relatively shorter wavelengths, for example, blue light, green light, or greenish blue light, and an electronic device, for example, an organic light-emitting device, including the organometallic compound may have an excellent out-coupling effect, thereby having high luminescence efficiency.

A highest occupied molecular orbital (HOMO) energy level, a lowest unoccupied molecular orbital (LUMO) energy level, a singlet (Si) energy level, and a triplet (T₁) energy level of some compounds of the organometallic compound represented by Formula 1 are evaluated by a density functional theory (DFT) of Gaussian program with molecular structure optimization based on B3LYP, and results are shown in Table 1.

TABLE 1 Compound No. HOMO (eV) LUMO (eV) S₁ (eV) T₁ (eV) 123 −4.773 −1.203 2.880 2.546 301 −4.787 −1.314 2.738 2.476 226 −4.780 −1.208 2.876 2.529 545 −4.767 −1.196 2.879 2.526

Referring to Table 1, it is confirmed that the organometallic compound represented by Formula 1 has such electrical characteristics that are suitable for use in an electronic device, for example, for use as a dopant for an organic light-emitting device.

Synthesis methods of the organometallic compound represented by Formula 1 may be recognizable by one of ordinary skill in the art by referring to Synthesis Examples provided below.

Therefore, the organometallic compound represented by Formula 1 may be suitable for use in an organic layer of an organic light-emitting device, for example, for use as a dopant in an emission layer of the organic layer. Another aspect of the present disclosure provides an organic light-emitting device including: a first electrode, a second electrode, and an organic layer disposed between the first electrode and the second electrode and including an emission layer, wherein the organic layer may include at least one organometallic compound represented by Formula 1.

The organic light-emitting device may have, due to the inclusion of an organic layer including the organometallic compound represented by Formula 1, a low driving voltage, high external quantum efficiency, a long lifespan, a low roll-off ratio, and excellent color purity.

The organometallic compound represented by Formula 1 may be used between a pair of electrodes of an organic light-emitting device. For example, the organometallic compound represented by Formula 1 may be included in the emission layer. In this regard, the organometallic compound may act as a dopant, and the emission layer may further include a host (that is, an amount of the organometallic compound represented by Formula 1 is smaller than an amount of the host). The emission layer may emit, for example, green light or blue light.

The expression “(an organic layer) includes at least one of the organometallic compound” as used herein may include a case in which “(an organic layer) includes identical organometallic compounds represented by Formula 1” and a case in which “(an organic layer) includes two or more different organometallic compounds represented by Formula 1”.

For example, the organic layer may include, as the organometallic compound, only Compound 1. In this regard, Compound 1 may exist only in the emission layer of the organic light-emitting device. In one or more embodiments, the organic layer may include, as the organometallic compound, Compound 1 and Compound 2. In this regard, Compound 1 and Compound 2 may exist in an identical layer (for example, Compound 1 and Compound 2 all may exist in an emission layer).

The first electrode may be an anode, which is a hole injection electrode, and the second electrode may be a cathode, which is an electron injection electrode; or the first electrode may be a cathode, which is an electron injection electrode, and the second electrode may be an anode, which is a hole injection electrode.

For example, in the organic light-emitting device, the first electrode is an anode, and the second electrode is a cathode, and the organic layer further includes a hole transport region between the first electrode and the emission layer and an electron transport region between the emission layer and the second electrode, and the hole transport region includes a hole injection layer, a hole transport layer, an electron blocking layer, or any combination thereof, and the electron transport region includes a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.

The term “organic layer” as used herein refers to a single layer and/or a plurality of layers disposed between the first electrode and the second electrode of an organic light-emitting device. The “organic layer” may include, in addition to an organic compound, an organometallic complex including metal.

FIGURE is a schematic cross-sectional view of an organic light-emitting device 10 according to an embodiment. Hereinafter, the structure of an organic light-emitting device according to an embodiment and a method of manufacturing an organic light-emitting device according to an embodiment will be described in connection with the FIGURE. The organic light-emitting device 10 includes a first electrode 11, an organic layer 15, and a second electrode 19, which are sequentially stacked.

A substrate may be additionally disposed under the first electrode 11 or above the second electrode 19. For use as the substrate, any substrate that is used in general organic light-emitting devices may be used, and the substrate may be a glass substrate or a transparent plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and water resistance.

The first electrode 11 may be formed by depositing or sputtering a material for forming the first electrode 11 on the substrate. The first electrode 11 may be an anode. The material for forming the first electrode 11 may include a material(s) with a high work function to facilitate hole injection. The first electrode 11 may be a reflective electrode, a semi-reflective electrode, or a transmissive electrode. The material for forming the first electrode may be, for example, indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), and zinc oxide (ZnO). In one or more embodiments, the material for forming the first electrode 11 may be metal, such as magnesium (Mg), aluminum (AI), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag).

The first electrode 11 may have a single-layered structure or a multi-layered structure including two or more layers. For example, the first electrode 11 may have a three-layered structure of ITO/Ag/ITO.

The organic layer 15 is disposed on the first electrode 11.

The organic layer 15 may include a hole transport region, an emission layer, and an electron transport region.

The hole transport region may be disposed between the first electrode 11 and the emission layer.

The hole transport region may include a hole injection layer, a hole transport layer, an electron blocking layer, a buffer layer, or any combination thereof.

The hole transport region may include only either a hole injection layer or a hole transport layer. In one or more embodiments, the hole transport region may have a hole injection layer/hole transport layer structure or a hole injection layer/hole transport layer/electron blocking layer structure, which are sequentially stacked in this stated order from the first electrode 11.

When the hole transport region includes a hole injection layer (HIL), the hole injection layer may be formed on the first electrode 11 by using one or more suitable methods, for example, vacuum deposition, spin coating, casting, and/or Langmuir-Blodgett (LB) deposition.

When a hole injection layer is formed by vacuum deposition, the deposition conditions may vary according to a material that is used to form the hole injection layer, and the structure and thermal characteristics of the hole injection layer. For example, the deposition conditions may include a deposition temperature of about 100° C. to about 500° C., a vacuum pressure of about 10⁻⁸ to about 10⁻³ torr, and a deposition rate of about 0.01 Å/sec to about 100 Å/sec. However, the deposition conditions are not limited thereto.

When the hole injection layer is formed using spin coating, coating conditions may vary according to the material used to form the hole injection layer, and the structure and thermal properties of the hole injection layer. For example, a coating speed may be from about 2,000 rpm to about 5,000 rpm, and a temperature at which a heat treatment is performed to remove a solvent after coating may be from about 80° C. to about 200° C. However, the coating conditions are not limited thereto.

Conditions for forming a hole transport layer and an electron blocking layer may be understood by referring to conditions for forming the hole injection layer.

The hole transport region may include m-MTDATA, TDATA, 2-TNATA, NPB, R-NPB, TPD, spiro-TPD, spiro-NPB, methylated-NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonicacid (PANI/CSA), polyaniline/poly(4-styrenesulfonate) (PANI/PSS), a compound represented by Formula 201 below, a compound represented by Formula 202 below, or any combination thereof:

Ar₁₀₁ to Ar₁₀₂ in Formula 201 may each independently be:

-   -   a phenylene group, a pentalenylene group, an indenylene group, a         naphthylene group, an azulenylene group, a heptalenylene group,         an acenaphthylene group, a fluorenylene group, a phenalenylene         group, a phenanthrenylene group, an anthracenylene group, a         fluoranthenylene group, a triphenylenylene group, a pyrenylene         group, a chrysenylenylene group, a naphthacenylene group, a         picenylene group, or a perylenylene group, each unsubstituted or         substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group,         a cyano group, a nitro group, an amino group, an amidino group,         a hydrazine group, a hydrazone group, a carboxylic acid group or         a salt thereof, a sulfonic acid group or a salt thereof, a         phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a         C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy         group, a C₃-C₁₀ cycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a         C₁-C₁₀ heterocycloalkyl group, a C₂-C₁₀ heterocycloalkenyl         group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀         arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent         non-aromatic condensed polycyclic group, a monovalent         non-aromatic condensed heteropolycyclic group, or any         combination thereof.

The designations xa and xb in Formula 201 may each independently be an integer from 0 to 5, or may be 0, 1 or 2. For example, xa may be 1 and xb may be 0.

R₁₀₁ to R₁₀₈, R₁₁₁ to R₁₁₉, and R₁₂₁ to R₁₂₄ in Formulae 201 and 202 may each independently be:

-   -   hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amino group, an amidino group, a         hydrazine group, a hydrazone group, a carboxylic acid group or a         salt thereof, a sulfonic acid group or a salt thereof, a         phosphoric acid group or a salt thereof, a C₁-C₁₀ alkyl group         (for example, a methyl group, an ethyl group, a propyl group, a         butyl group, pentyl group, a hexyl group, and the like), or a         C₁-C₁₀ alkoxy group (for example, a methoxy group, an ethoxy         group, a propoxy group, a butoxy group, a pentoxy group, and the         like);     -   a C₁-C₁₀ alkyl group or a C₁-C₁₀ alkoxy group, each substituted         with deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano         group, a nitro group, an amino group, an amidino group, a         hydrazine group, a hydrazone group, a carboxylic acid group or a         salt thereof, a sulfonic acid group or a salt thereof, a         phosphoric acid group or a salt thereof, or any combination         thereof;     -   a phenyl group, a naphthyl group, an anthracenyl group, a         fluorenyl group, or a pyrenyl group, each unsubstituted or         substituted with deuterium, —F, —Cl, —Br, —I, a hydroxyl group,         a cyano group, a nitro group, an amino group, an amidino group,         a hydrazine group, a hydrazone group, a carboxylic acid group or         a salt thereof, a sulfonic acid group or a salt thereof, a         phosphoric acid group or a salt thereof, a C₁-C₁₀ alkyl group, a         C₁-C₁₀ alkoxy group, or any combination thereof

R₁₀₉ in Formula 201 may be:

-   -   a phenyl group, a naphthyl group, an anthracenyl group, or a         pyridinyl group, each unsubstituted or substituted with         deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a         nitro group, an amino group, an amidino group, a hydrazine         group, a hydrazone group, a carboxylic acid group or a salt         thereof, a sulfonic acid group or a salt thereof, a phosphoric         acid group or a salt thereof, a C₁-C₂₀ alkyl group, a C₁-C₂₀         alkoxy group, a phenyl group, a naphthyl group, an anthracenyl         group, a pyridinyl group, or any combination thereof.

In one or more embodiments, the compound represented by Formula 201 may be represented by Formula 201A below:

Detailed descriptions of R₁₀₁, R₁₁₁, R₁₁₂, and R₁₀₉ in Formula 201A are the same as described above.

For example, the hole transport region may include at least one of compounds HT1 to HT20 illustrated below:

A thickness of the hole transport region may be from about 100 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When the hole transport region includes a hole injection layer, a hole transport layer, an electron blocking layer or combination thereof, a thickness of the hole injection layer may be in a range of about 100 Å to about 10000 Å, for example, about 100 Å to about 1,000 Å, and a thickness of the hole transport layer may be in a range of about 50 Å to about 2,000 Å, for example about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are within these ranges, satisfactory hole transporting characteristics may be obtained without a substantial increase in driving voltage.

The hole transport region may further include, in addition to these materials, a charge-generation material for the improvement of conductive properties. The charge-generation material may be homogeneously or non-homogeneously dispersed in the hole transport region.

The charge-generation material may be, for example, a p-dopant. The p-dopant may be a quinone derivative, a metal oxide, a cyano group-containing compound, or any combination thereof. Non-limiting examples of the p-dopant are a quinone derivative, such as tetracyanoquinonedimethane (TCNQ), 2,3,5,6-tetrafluoro-tetracyano-1,4-benzoquinonedimethane (F4-TCNQ) and F6-TCNNQ; a metal oxide, such as a tungsten oxide or a molybdenum oxide; and a cyano group-containing compound, such as Compound HT-D1 below:

The hole transport region may include a buffer layer.

Also, the buffer layer may compensate for an optical resonance distance according to a wavelength of light emitted from the emission layer, and thus, efficiency of a formed organic light-emitting device may be improved.

Meanwhile, when the hole transport region includes an electron blocking layer, a material for the electron blocking layer may be materials for the hole transport region described above, materials for a host to be explained later, or any combination thereof. However, the material for the electron blocking layer is not limited thereto. For example, when the hole transport region includes an electron blocking layer, a material for the electron blocking layer may be mCP, which will be explained later.

Then, an emission layer may be formed on the hole transport region by vacuum deposition, spin coating, casting, LB deposition, or the like. When the emission layer is formed by vacuum deposition or spin coating, the deposition or coating conditions may be similar to those applied in forming the hole injection layer although the deposition or coating conditions may vary according to a compound that is used to form the emission layer.

The emission layer may include a host and a dopant, and the dopant may include the organometallic compound represented by Formula 1.

The host may include TPBi, TBADN, ADN (also referred to as “DNA”), CBP, CDBP, TCP, mCP, Compounds H50, Compound H51, Compound H52, or any combination thereof:

When the organic light-emitting device is a full-color organic light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, and/or a blue emission layer. In one or more embodiments, due to a stacked structure including a red emission layer, a green emission layer, and/or a blue emission layer, the emission layer may emit white light.

When the emission layer includes a host and a dopant, an amount of the dopant may be in a range of about 0.01 parts by weight to about 15 parts by weight based on 100 parts by weight of the host.

A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer is within this range, excellent light-emission characteristics may be obtained without a substantial increase in driving voltage.

Then, an electron transport region may be disposed on the emission layer.

The electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.

For example, the electron transport region may have a hole blocking layer/electron transport layer/electron injection layer structure or an electron transport layer/electron injection layer structure. The electron transport layer may have a single-layered structure or a multi-layered structure including two or more different materials.

Conditions for forming the hole blocking layer, the electron transport layer, and the electron injection layer which constitute the electron transport region may be understood by referring to the conditions for forming the hole injection layer.

When the electron transport region includes a hole blocking layer, the hole blocking layer may include, for example, BCP, Bphen, BAlq, or any combination thereof:

A thickness of the hole blocking layer may be from about 20 Å to about 1,000 Å, for example, about 30 Å to about 600 Å. When the thickness of the hole blocking layer is within these ranges, the hole blocking layer may have excellent hole blocking characteristics without a substantial increase in driving voltage.

The electron transport layer may include BCP, Bphen, Alq₃, BAlq, TAZ, NTAZ, or any combination thereof:

In one or more embodiments, the electron transport layer may include at least one of ET1 to ET25:

A thickness of the electron transport layer may be from about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. When the thickness of the electron transport layer is within the range described above, the electron transport layer may have satisfactory electron transport characteristics without a substantial increase in driving voltage.

Also, the electron transport layer may further include, in addition to the materials described above, a metal-containing material.

The metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (LiQ), Compound ET-D2, or combination thereof:

The electron transport region may include an electron injection layer that promotes flow of electrons from the second electrode 19 thereinto.

The electron injection layer may include LiF, NaCl, CsF, Li₂O, BaO, or any combination thereof.

A thickness of the electron injection layer may be from about 1 Å to about 100 Å, for example, about 3 Å to about 90 Å. When a thickness of the electron injection layer is within these ranges, satisfactory electron injection characteristics may be obtained without substantial increase in driving voltage.

The second electrode 19 is disposed on the organic layer 15. The second electrode 19 may be a cathode. A material for forming the second electrode 19 may be a metal, an alloy, an electrically conductive compound, and a combination thereof, which have a relatively low work function. For example, lithium (Li), magnesium (Mg), aluminum (AI), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), or magnesium-silver (Mg—Ag) may be formed as the material for forming the second electrode 19. To manufacture a top-emission type light-emitting device, a transmissive electrode formed using ITO or IZO may be used as the second electrode 19.

Hereinbefore, the organic light-emitting device according to an embodiment has been described in connection with the FIGURE.

In one or more embodiments, the organic light-emitting device may be included in an electronic apparatus. Accordingly, provided is an electronic apparatus including the organic light-emitting device. The electronic apparatus may include, for example, a display, an illuminator, and a sensor.

Another aspect of the present disclosure provides a diagnostic composition including at least one of the organometallic compound represented by Formula 1.

The organometallic compound represented by Formula 1 provides high luminescent efficiency. Accordingly, a diagnostic composition including the organometallic compound may have high diagnostic efficiency.

The diagnostic composition may be used in various applications including a diagnosis kit, a diagnosis reagent, a biosensor, and a biomarker.

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear or branched saturated aliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms, and the term “C₁-C₆₀ alkylene group” as used herein refers to a divalent group having the same structure as the C₁-C₆₀ alkyl group.

Non-limiting examples of the C₁-C₆₀ alkyl group, the C₁-C₂₀ alkyl group, and/or the C₁-C₁₀ alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, and a tert-decyl group, each unsubstituted or substituted with a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neopentyl group, an isopentyl group, a sec-pentyl group, a 3-pentyl group, a sec-isopentyl group, an n-hexyl group, an isohexyl group, a sec-hexyl group, a tert-hexyl group, an n-heptyl group, an isoheptyl group, a sec-heptyl group, a tert-heptyl group, an n-octyl group, an isooctyl group, a sec-octyl group, a tert-octyl group, an n-nonyl group, an isononyl group, a sec-nonyl group, a tert-nonyl group, an n-decyl group, an isodecyl group, a sec-decyl group, a tert-decyl group, or any combination thereof. For example, Formula 9-33 may be a branched C alkyl group, and may be a tert-butyl group that is substituted with two methyl groups.

The term “C₁-C₆₀ alkoxy group” used herein refers to a monovalent group represented by —OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group). Non-limiting examples of the C₁-C₆₀ alkoxy group, the C₁-C₂₀ alkoxy group, or the C₁-C₁₀ alkoxy group include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a pentoxy group.

The term “C₂-C₆ alkenyl group” as used herein refers to a hydrocarbon group having at least one carbon-carbon double bond in the middle or at the terminus of the C₂-C₆₀ alkenyl group, and examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀ alkenylene group” as used herein refers to a divalent group having the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a hydrocarbon group having at least one carbon-carbon triple bond in the middle or at the terminus of the C₂-C₆₀ alkynyl group, and examples thereof include an ethynyl group, and a propynyl group. The term “C₂-C₆₀ alkynylene group” as used herein refers to a divalent group having the same structure as the C₂-C₆₀ alkynyl group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalent saturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, and the term “C₃-C₁₀ cycloalkylene group” as used herein refers to a divalent group having the same structure as the C₃-C₁₀ cycloalkyl group.

Non-limiting examples of the C₃-C₁₀ cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, an adamantyl group, a bicyclo[1.1.1]pentyl group, a bicyclo[2.1.1]hexyl group, a bicyclo[2.2.1]heptyl group (a norbornyl group), and a bicyclo[2.2.2]octyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to a monovalent saturated monocyclic group having at least one N, O, P, Si, B, Se, Ge, S, or any combination thereof as a ring-forming atom and 1 to 10 carbon atoms, and the term “C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalent group having the same structure as the C₁-C₁₀ heterocycloalkyl group.

Non-limiting examples of the C₁-C₁₀ heterocycloalkyl group include a silolanyl group, a silinanyl group, a tetrahydrofuranyl group, a tetrahydro-2H-pyranyl group, and a tetrahydrothiophenyl group.

The term “C₃-C₁₀ cycloalkenyl group” as used herein refers to a monovalent monocyclic group that has 3 to 10 carbon atoms and at least one carbon-carbon double bond in the ring thereof and no aromaticity, and non-limiting examples thereof include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group” as used herein refers to a divalent group having the same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₂-C₁₀ heterocycloalkenyl group” as used herein refers to a monovalent monocyclic group that has at least one N, O, P, Si, B, Ge, Se, S, or any combination thereof as a ring-forming atom, 2 to 10 carbon atoms, and at least one double bond in its ring. Examples of the C₂-C₁₀ heterocycloalkenyl group include a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C₂-C₁₀ heterocycloalkenylene group” as used herein refers to a divalent group having the same structure as the C₂-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms, and the term “C₆-C₆₀ arylene group” as used herein refers to a divalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. Non-limiting examples of the C₆-C₆₀ aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylene group each include two or more rings, the rings may be fused to each other.

The term “C₇-C₆₀ alkylaryl group” used herein refers to a C₆-C₅₉ arylene group substituted with at least one C₁-C₅₄ alkyl group.

The term “C₁-C₆ heteroaryl group” as used herein refers to a monovalent group having a heterocyclic aromatic system that has at least one N, O, P, Si, B, Se, Ge, S, or any combination thereof as a ring-forming atom, in addition to 1 to 60 carbon atoms. The term “C₁-C₆₀ heteroarylene group” as used herein refers to a divalent group having a heterocyclic aromatic system that has at least one heteroatom N, O, P, Si, B, Se, Ge, S, or any combination thereof as a ring-forming atom, in addition to 1 to 60 carbon atoms. Non-limiting examples of the C₁-C₆₀ heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, and an isoquinolinyl group. When the C₁-C₆₀ heteroaryl group and the C₁-C₆₀ heteroarylene group each include two or more rings, the rings may be fused to each other.

The term “C₂-C₆₀ alkylheteroaryl group” used herein refers to a C₁-C₅₉ heteroarylene group substituted with at least one C₁-C₅₉ alkyl group.

The term “C₆-C₆₀ aryloxy group” used herein indicates —OA₁₀₂ (wherein A₁₀₂ is the C₆-C₆₀ aryl group), a C₆-C₆₀ arylthio group used herein indicates —SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group), and a C₁-C₆₀ alkylthio group used herein indicates —SA₁₀₄ (wherein A₁₀₄ is the C₁-C₆₀ alkyl group).

The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group (for example, having 8 to 60 carbon atoms) having two or more rings condensed to each other, only carbon atoms as ring-forming atoms, and no aromaticity in its entire molecular structure. Examples of the monovalent non-aromatic condensed polycyclic group include a fluorenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group (for example, having 2 to 60 carbon atoms) having two or more rings condensed to each other, a heteroatom N, O, P, Si, and S, other than carbon atoms, as a ring-forming atom, and no aromaticity in its entire molecular structure. Non-limiting examples of the monovalent non-aromatic condensed heteropolycyclic group include a carbazolyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

The term “C₅-C₃₀ carbocyclic group” as used herein refers to a saturated or unsaturated cyclic group having, as a ring-forming atom, 5 to 30 carbon atoms only. The C₅-C₃₀ carbocyclic group may be a monocyclic group or a polycyclic group. The term “C₅-C₃₀ carbocyclic group (which is unsubstituted or substituted with at least one R_(10a))” may include, for example, an adamantane group, a norbornene group, a bicyclo[1.1.1]pentane group, a bicyclo[2.1.1]hexane group, a bicyclo[2.2.1]heptane group (a norbornane group), a bicyclo[2.2.2]octane group, a cyclopentane group, a cyclohexane group, a cyclohexene group, a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a 1,2,3,4-tetrahydronaphthalene group, cyclopentadiene group, and a fluorene group, each being unsubstituted or substituted with at least one R_(10a).

The term “C₁-C₃₀ heterocyclic group” as used herein refers to a saturated or unsaturated cyclic group having, as a ring forming atom, at least one N, O, P, Si, Se, Ge, B, S, or any combination thereof other than 1 to 30 carbon atoms. The C₁-C₃₀ heterocyclic group may be a monocyclic group or a polycyclic group. The “C₁-C₃₀ heterocyclic group (which is unsubstituted or substituted with at least one R_(10a))” may include, for example, a thiophene group, a furan group, a pyrrole group, a silole group, a borole group, a phosphole group, a selenophene group, a germole group, a benzothiophene group, a benzofuran group, an indole group, an indene group, a benzosilole group, a benzoborole group, a benzophosphole group, a benzoselenophene group, a benzogermole group, a dibenzothiophene group, a dibenzofuran group, a carbazole group, a dibenzosilole group, a dibenzoborole group, a dibenzophosphole group, a dibenzoselenophene group, a dibenzogermole group, a dibenzothiophene 5-oxide group, 9H-fluorene-9-one group, a dibenzothiophene 5,5-dioxide group, an azabenzothiophene group, an azabenzofuran group, an azaindole group, an azaindene group, an azabenzosilole group, an azabenzoborole group, an azabenzophosphole group, an azabenzoselenophene group, an azabenzogermole group, an azadibenzothiophene group, an azadibenzofuran group, an azacarbazole group, an azafluorene group, an azadibenzosilole group, an azadibenzoborole group, an azadibenzophosphole group, an azadibenzoselenophene group, an azadibenzogermole group, an azadibenzothiophene 5-oxide group, an aza-9H-fluorene-9-one group, an azadibenzothiophene 5,5-dioxide group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isooxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, and a 5,6,7,8-tetrahydroquinoline group, each being unsubstituted or substituted with at least one R_(10a).

The term “(C₁-C₂₀ alkyl)‘X’ group” as used herein refers to a ‘X’ group substituted with at least one C₁-C₂₀ alkyl group. For example, the term “(C₁-C₂₀ alkyl)C₃-C₁₀ cycloalkyl group” as used herein refers to a C₃-C₁₀ cycloalkylene group substituted with at least one C₁-C₂₀ alkyl group and the term “(C₁-C₂₀ alkyl)phenyl group” as used herein refers to a phenylene group substituted with at least one C₁-C₂₀ alkyl group. An example of a (C₁ alkyl)phenyl group is a toluyl group.

The terms “an azaindole group, an azabenzoborole group, an azabenzophosphole group, an azaindene group, an azabenzosilole group, an azabenzogermole group, an azabenzothiophene group, an azabenzoselenophene group, an azabenzofuran group, an azacarbazole group, an azadibenzoborole group, an azadibenzophosphole group, an azafluorene group, an azadibenzosilole group, an azadibenzogermole group, an azadibenzothiophene group, an azadibenzoselenophene group, an azadibenzofuran group, an azadibenzothiophene 5-oxide group, an aza-9H-fluorene-9-one group, and an azadibenzothiophene 5,5-dioxide group” respectively refer to a heterocyclic group having the same backbone as “an indole group, a benzoborole group, a benzophosphole group, an indene group, a benzosilole group, a benzogermole group, a benzothiophene group, a benzoselenophene group, a benzofuran group, a carbazole group, a dibenzoborole group, a dibenzophosphole group, a fluorene group, a dibenzosilole group, a dibenzogermole group, a dibenzothiophene group, a dibenzoselenophene group, a dibenzofuran group, a dibenzothiophene 5-oxide group, 9H-fluorene-9-one group, and a dibenzothiophene 5,5-dioxide group” in which at least one of the carbon atoms constituting the cyclic groups is substituted with a nitrogen.

A substituent of the substituted C₅-C₃₀ carbocyclic group, the substituted C₁-C₃₀ heterocyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₁-C₆₀ alkylthio group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₂-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₇-C₆₀ alkylaryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted C₂-C₆₀ alkylheteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may each independently be:

-   -   deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H,         —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino         group, an amidino group, a hydrazine group, a hydrazone group, a         carboxylic acid group or a salt thereof, a sulfonic acid group         or a salt thereof, a phosphoric acid group or a salt thereof, a         C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl         group, a C₁-C₆₀ alkoxy group, or a C₁-C₆₀ alkylthio group;     -   a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl         group, a C₁-C₆₀ alkoxy group, or a C₁-C₆₀ alkylthio group, each         substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H,         —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a         nitro group, an amino group, an amidino group, a hydrazine         group, a hydrazone group, a carboxylic acid group or a salt         thereof, a sulfonic acid group or a salt thereof, a phosphoric         acid group or a salt thereof, a C₃-C₁₀ cycloalkyl group, a         C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a         C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₇-C₆₀         alkylaryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a C₂-C₆₀ alkylheteroaryl         group, a monovalent non-aromatic condensed polycyclic group, a         monovalent non-aromatic condensed heteropolycyclic group,         —N(Q₁₁)(Q₁₂), —Ge(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇),         —P(═O)(Q₁₈)(Q₁₉), —P(Q₁₈)(Q₁₉), or any combination thereof;     -   a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a         C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a         C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio         group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic         condensed polycyclic group, or a monovalent non-aromatic         condensed heteropolycyclic group, each substituted with         deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H,         —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino         group, an amidino group, a hydrazine group, a hydrazone group, a         carboxylic acid group or a salt thereof, a sulfonic acid group         or a salt thereof, a phosphoric acid group or a salt thereof, a         C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl         group, a C₁-C₆₀ alkoxy group, a C₁-C₆₀ alkylthio group, a C₃-C₁₀         cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀         cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀         aryl group, a C₇-C₀ alkylaryl group, a C₆-C₆₀ aryloxy group, a         C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a C₂-C₆₀         alkylheteroaryl group, a monovalent non-aromatic condensed         polycyclic group, a monovalent non-aromatic condensed         heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Ge(Q₂₃)(Q₂₄)(Q₂₅),         —B(Q₂₆)(Q₂₇), —P(═O)(Q₂₈)(Q₂₉), —P(Q₂₈)(Q₂₉), or any combination         thereof;     -   —N(Q₃₁)(Q₃₂), —Ge(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), —P(═O)(Q₃₈)(Q₃₉)         or —P(Q₃₈)(Q₃₉); or     -   any combination thereof.

In the present specification, Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ may each independently be hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; an amino group; an amidino group; a hydrazine group; a hydrazone group; a carboxylic acid group or a salt thereof; a sulfonic acid group or a salt thereof; a phosphoric acid group or a salt thereof; a C₁-C₆₀ alkyl group unsubstituted or substituted with deuterium, a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group, or any combination thereof; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a C₃-C₁₀ cycloalkyl group; a C₁-C₁₀ heterocycloalkyl group; a C₃-C₁₀ cycloalkenyl group; a C₂-C₁₀ heterocycloalkenyl group; a C₆-C₆₀ aryl group unsubstituted or substituted with deuterium, a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group, or any combination thereof; a C₆-C₆₀ aryloxy group; a C₆-C₆₀ arylthio group; a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group; or a monovalent non-aromatic condensed heteropolycyclic group.

For example, in the present specification, Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ may each independently be

-   -   —CH₃, —CD₃, —CD₂H, —CDH₂, —CH₂CH₃, —CH₂CD₃, —CH₂CD₂H, —CH₂CDH₂,         —CHDCH₃, —CHDCD₂H, —CHDCDH₂, —CHDCD₃, —CD₂CD₃, —CD₂CD₂H, or         —CD₂CDH₂; or     -   an n-propyl group, an isopropyl group, an n-butyl group, a         sec-butyl group, an isobutyl group, a tert-butyl group, an         n-pentyl group, a tert-pentyl group, a neopentyl group, an         isopentyl group, a sec-pentyl group, a 3-pentyl group, a         sec-isopentyl group, a phenyl group, a biphenyl group, or a         naphthyl group, each unsubstituted or substituted with         deuterium, a C₁-C₁₀ alkyl group, a phenyl group, or any         combination thereof.

Hereinafter, a compound and an organic light-emitting device according to embodiments are described in detail with reference to Synthesis Example and Examples. However, the organic light-emitting device is not limited thereto. The wording “B was used instead of A” used in describing Synthesis Examples means that an amount of A used was identical to an amount of B used, in terms of a molar equivalent.

EXAMPLES Synthesis Example 1 (Compound 125) Synthesis of Compound 125A

4-isobutyl-2-phenyl-5-(trimethylsilyl)pyridine (8.0 g, 28.4 mmol) and iridium chloride (4.4 g, 12.6 mmol) were mixed with 120 mL of ethoxyethanol and 40 mL of distilled water. The mixed solution was stirred under reflux for 24 hours, and the temperature was lowered to room temperature. A solid produced therefrom was separated by filtration, and then, washed thoroughly with water/methanol/hexane in the stated order. The resulting solid was then dried in a vacuum oven, thereby obtaining 7.5 g of Compound 125A (yield of 75%).

Synthesis of Compound 125B

Compound 125A (1.6 g, 1.0 mmol) was mixed with 45 ml of methylene chloride (MC), and a mixture of AgOTf (Silver trifluoromethanesulfonate) (0.5 g, 2.1 mmol) and 15 ml of methanol was added thereto. Afterwards, the mixed solution was stirred at room temperature for 18 hours while blocking the light with aluminum foil. The resulting solution was then filtered through celite to remove a solid produced therefrom, and the solvent was removed from the filtrate under reduced pressure, and a solid (Compound 125B) produced therefrom was used in the next reaction without additional purification.

Synthesis of Compound 125

Compound 125B (2.0 g, 2.1 mmol) and 8-(4-isobutylpyridin-2-yl)-2-methylbenzofuro[2,3-b]pyridine (0.8 g, 2.4 mmol) were mixed with 40 ml of a mixture of MC and ethanol. The mixed solution was stirred under reflux for 18 hours, and the temperature was lowered down. The resulting solution was filtered, and a solid obtained therefrom was washed thoroughly with ethanol and hexane. The resulting product was subjected to column chromatography under the MC: hexane conditions, thereby obtaining 0.8 g of Compound 125 (yield of 36%). Substances of the compound were identified by the Mass Spectrum and HPLC analysis.

HRMS(MALDI) calcd for C₅₇H₆₇IrN₄OSi₂: m/z 1072.4483 Found: 1072.4490

Synthesis Example 2 (Compound 128)

0.9 g of Compound 128 (yield of 40%) was obtained in the same manner as in the synthesis of Compound 125 according to Synthesis Example 1, except that 8-(4-(cyclopentylmethyl)pyridin-2-yl)-2-methylbenzofuro[2,3-b]pyridine was used instead of 8-(4-isobutylpyridin-2-yl)-2-methylbenzofuro[2,3-b]pyridine. Substances of the compound were identified by the Mass Spectrum and HPLC analysis.

HRMS(MALDI) calcd for C₅₉H₆₉IrN₄OSi₂: m/z 1098.4639, Found: 1098.4631

Synthesis Example 3 (Compound 163) Synthesis of Compound 163A

6.5 g of Compound 163A (yield of 65%) was obtained in the same manner as in the synthesis of Compound 125A according to Synthesis Example 1, except that 4-(cyclopentylmethyl)-2-phenyl-5-(trimethylsilyl)pyridine was used instead of 4-isobutyl-2-phenyl-5-(trimethylsilyl)pyridine.

Synthesis of Compound 163B

Compound 163B was obtained in the same manner as in the synthesis of Compound 125B according to Synthesis Example 1, except that Compound 163A was used instead of Compound 125A. Compound 163B thus obtained was used in the next reaction without additional purification.

Synthesis of Compound 163

0.65 g of Compound 163 (yield of 29%) was obtained in the same manner as in the synthesis of Compound 125 according to Synthesis Example 1, except that Compound 163B was used instead of Compound 125B and 8-(4-isopropylpyridin-2-yl)-2-methylbenzofuro[2,3-b]pyridine was used instead of 8-(4-isobutylpyridin-2-yl)-2-methylbenzofuro[2,3-b]pyridine. Substances of the compound were identified by the Mass Spectrum and HPLC analysis.

HRMS(MALDI) calcd for C₆₀H₆₉IrN₄OSi₂: m/z 1110.4639, Found: 1110.4644

Synthesis Example 4 (Compound 365)

0.85 g of Compound 365 (yield of 37%) was obtained in the same manner as in the synthesis of Compound 125 according to Synthesis Example 1, except that 6-(4-isobutylpyridin-2-yl)-2-methylbenzofuro[2,3-b]pyridine was used instead of 8-(4-isobutylpyridin-2-yl)-2-methylbenzofuro[2,3-b]pyridine. Substances of the compound were identified by the Mass Spectrum and HPLC analysis.

HRMS(MALDI) calcd for C₅₇H₆₇IrN₄OSi₂: m/z 1072.4483 Found: 1072.4488

Synthesis Example 5 (Compound 505) Synthesis of Compound 505A

7.1 g of Compound 505A (yield of 71%) was obtained in the same manner as in the synthesis of Compound 125A according to Synthesis Example 1, except that 4-isobutyl-D₂-2-phenyl-5-(trimethylsilyl)pyridine was used instead of 4-isobutyl-2-phenyl-5-(trimethylsilyl)pyridine.

Synthesis of Compound 505B

Compound 505B was obtained in the same manner as in the synthesis of Compound 125B according to Synthesis Example 1, except that Compound 505A was used instead of Compound 125A. Compound 505B thus obtained was used in the next reaction without additional purification.

Synthesis of Compound 505

0.5 g of Compound 505 (yield of 22%) was obtained in the same manner as in the synthesis of Compound 125 according to Synthesis Example 1, except that Compound 505B was used instead of Compound 125B and 8-(4-isobutylpyridin-2-yl-D₂)-2-methyl(D₃)benzofuro[2,3-b]pyridine was used instead of 8-(4-isobutylpyridin-2-yl)-2-methylbenzofuro[2,3-b]pyridine. Substances of the compound were identified by the Mass Spectrum and HPLC analysis.

HRMS(MALDI) calcd for C₅₇H₅₈D₉IrN₄OSi₂: m/z 1081.5048, Found: 1081.5052

Synthesis Example 6 (Compound 526) Synthesis of Compound 526A

6.6 g of Compound 526A (yield of 66%) was obtained in the same manner as in the synthesis of Compound 125A according to Synthesis Example 1, except that 4-neopentyl(D₂)-2-phenyl-5-(trimethylsilyl)pyridine was used instead of 4-isobutyl-2-phenyl-5-(trimethylsilyl)pyridine.

Synthesis of Compound 526B

Compound 526B was obtained in the same manner as in the synthesis of Compound 125B according to Synthesis Example 1, except that Compound 526A was used instead of Compound 125A. Compound 526B thus obtained was used in the next reaction without additional purification.

Synthesis of Compound 526

1.0 g of Compound 526 (yield of 44%) was obtained in the same manner as in the synthesis of Compound 125 according to Synthesis Example 1, except that Compound 526B was used instead of Compound 125B and 2-isopropyl(D)-8-(4-neopentyl(D₂)pyridin-2-yl)benzofuro[2,3-b]pyridine was used instead of 8-(4-isobutylpyridin-2-yl)-2-methylbenzofuro[2,3-b]pyridine. Substances of the compound were identified by the Mass Spectrum and HPLC analysis.

HRMS(MALDI) calcd for C₆₂H₇₀D₇IrN₄OSi₂: m/z 1149.5705, Found: 1149.5700

Synthesis Example 7 (Compound 676)

0.8 g of Compound 676 (yield of 41%) was obtained in the same manner as in the synthesis of Compound 125 according to Synthesis Example 1, except that 2-phenyl-8-(4-(propan-2-yl-2-d)pyridin-2-yl)benzofuro[2,3-b]pyridine was used instead of 8-(4-isobutylpyridin-2-yl)-2-methylbenzofuro[2,3-b]pyridine. Substances of the compound were identified by the Mass Spectrum and HPLC analysis.

HRMS(MALDI) calcd for C₆₁H₆₆IrN₄OSi₂: m/z 1121.4545, Found: 1121.4549

Synthesis Example 8 (Compound 806) Synthesis of Compound 806A

3.7 g of Compound 806A (yield of 74%) was obtained in the same manner as in the synthesis of Compound 125A according to Synthesis Example 1, except that 4-isobutyl-2-phenyl-5-(trimethylgermyl)pyridine was used instead of 4-isobutyl-2-phenyl-5-(trimethylsilyl)pyridine.

Synthesis of Compound 806B

Compound 806B was obtained in the same manner as in the synthesis of Compound 125B according to Synthesis Example 1, except that Compound 806A was used instead of Compound 125A. Compound 806B thus obtained was used in the next reaction without additional purification.

Synthesis of Compound 806

0.53 g of Compound 806 (yield of 35%) was obtained in the same manner as in the synthesis of Compound 125 according to Synthesis Example 1, except that Compound 806B was used instead of Compound 125B and 2-methyl(D₃)-8-(4-neopentylpyridin-2-yl)benzofuro[2,3-b]pyridine was used instead of 8-(4-isobutylpyridin-2-yl)-2-methylbenzofuro[2,3-b]pyridine. Substances of the compound were identified by the Mass Spectrum and HPLC analysis.

HRMS(MALDI) calcd for C₅₈H₆₆D₃Ge₂IrN₄O: m/z 1181.3712, Found: 1181.3706

Synthesis Example 9 (Compound 865)

0.69 g of Compound 865 (yield of 31%) was obtained in the same manner as in the synthesis of Compound 125 according to Synthesis Example 1, except that Compound 806B was used instead of Compound 125B and 2-(dibenzo[b,d]furan-4-yl)-4-isobutylpyridine was used instead of 8-(4-isobutylpyridin-2-yl)-2-methylbenzofuro[2,3-b]pyridine. Substances of the compound were identified by the Mass Spectrum and HPLC analysis.

HRMS(MALDI) calcd for C₅₇H₆₆Ge₂IrN₃O: m/z 1149.3259, Found: 1149.3251

Synthesis Example 10 (Compound 1365) Synthesis of Compound 1365A

4.6 g of Compound 1365A (yield of 62%) was obtained in the same manner as in the synthesis of Compound 125A according to Synthesis Example 1, except that 4-isobutyl(D₂)-2-(p-tolyl(D₃))-5-(trimethylgermyl)pyridine was used instead of 4-isobutyl-2-phenyl-5-(trimethylsilyl)pyridine.

Synthesis of Compound 1365B

Compound 1365B was obtained in the same manner as in the synthesis of Compound 125B according to Synthesis Example 1, except that Compound 1365A was used instead of Compound 125A. Compound 1365B thus obtained was used in the next reaction without additional purification.

Synthesis of Compound 1365

0.43 g of Compound 1365 (yield of 28%) was obtained in the same manner as in the synthesis of Compound 125 according to Synthesis Example 1, except that Compound 1365B was used instead of Compound 125B and 2-(7-methyl(D₃)dibenzo[b,d]thiophen-4-yl)-4-neopentyl(D₂)pyridine was used instead of 8-(4-isobutylpyridin-2-yl)-2-methylbenzofuro[2,3-b]pyridine. Substances of the compound were identified by the Mass Spectrum and HPLC analysis.

HRMS(MALDI) calcd for C₆₁H₅₉D₁₅Ge₂IrN₃O: m/z 1236.4598, Found: 1236.4591

Synthesis Example 11 (Compound 1497) Synthesis of Compound 1497A

4.2 g of Compound 1497A (yield of 58%) was obtained in the same manner as in the synthesis of Compound 125A according to Synthesis Example 1, except that 2-phenyl-4-(propan-2-yl-2-d)-5-(trimethylgermyl)pyridine was used instead of 4-isobutyl-2-phenyl-5-(trimethylsilyl)pyridine.

Synthesis of Compound 1497B

Compound 1497B was obtained in the same manner as in the synthesis of Compound 125B according to Synthesis Example 1, except that Compound 1497A was used instead of Compound 125A. Compound 1497B thus obtained was used in the next reaction without additional purification.

Synthesis of Compound 1497

0.53 g of Compound 1497 (yield of 34%) was obtained in the same manner as in the synthesis of Compound 125 according to Synthesis Example 1, except that Compound 1497B was used instead of Compound 125B and 2-(2,6-dimethylphenyl)-8-(4-(2,2-dimethylpropyl-1,1-d2)-5-(methyl-d3)pyridin-2-yl)benzofuro[2,3-b]pyridine was used instead of 8-(4-isobutylpyridin-2-yl)-2-methylbenzofuro[2,3-b]pyridine Substances of the compound were identified by the Mass Spectrum and HPLC analysis.

HRMS(MALDI) calcd for C₆₄H₆₆D₇Ge₂IrN₄O: m/z 1261.4277, Found: 1261.4271

Synthesis Example 12 (Compound 1505) Synthesis of Compound 1505A

4.3 g of Compound 1505A (yield of 49%) was obtained in the same manner as in the synthesis of Compound 125A according to Synthesis Example 1, except that 4-(2,2-dimethylpropyl-1,1-d2)-2-phenyl-5-(trimethylgermyl)pyridine was used instead of 4-isobutyl-2-phenyl-5-(trimethylsilyl)pyridine.

Synthesis of Compound 1505B

Compound 1505B was obtained in the same manner as in the synthesis of Compound 125B according to Synthesis Example 1, except that Compound 1505A was used instead of Compound 125A. Compound 1505B thus obtained was used in the next reaction without additional purification.

Synthesis of Compound 1505

0.32 g of Compound 1505 (yield of 27%) was obtained in the same manner as in the synthesis of Compound 125 according to Synthesis Example 1, except that Compound 1505B was used instead of Compound 125B and 4-(2-methylpropyl-1,1-d2)-2-(8-phenyldibenzo[b,d]furan-4-yl)pyridine was used instead of 8-(4-isobutylpyridin-2-yl)-2-methylbenzofuro[2,3-b]pyridine Substances of the compound were identified by the Mass Spectrum and HPLC analysis.

HRMS(MALDI) calcd for C₆₅H₆₈D₆Ge₂IrN₃O: m/z 1259.4261, Found: 1259.4255

Example 1

As an anode, a glass substrate on which ITO/Ag/ITO was formed to a thickness of 70 Å/1,000 Å/70 Å was cut to a size of 50 mm×50 mm×0.5 mm, sonicated with isopropyl alcohol and pure water each for 5 minutes, and then, cleaned by exposure to ultraviolet rays and ozone for 30 minutes. Then, the anode was provided to a vacuum deposition apparatus.

2-TNATA was vacuum-deposited on the anode to form a hole injection layer having a thickness of 600 Å, and 4,4′-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (hereinafter, referred to as NPB) was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 1,350 Å.

Next, CBP (as a host) and Compound 125 (as a dopant) were co-deposited at a weight ratio of 98:2 on the hole transport layer to form an emission layer having a thickness of 400 Å.

Then, BCP was vacuum-deposited on the emission layer to form a hole blocking layer having a thickness of 50 Å, and Alq₃ was vacuum-deposited on the hole blocking layer to form an electron transport layer having a thickness of 350 Å. LiF was vacuum-deposited on the electron transport layer to form an electron injection layer having a thickness of 10 Å, and Mg and Ag were co-deposited at a weight ratio of 90:10 on the electron injection layer to form a cathode having a thickness of 120 Å, thereby completing the manufacture of an organic light-emitting device.

Examples 2 to 12 and Comparative Examples A and B

Organic light-emitting devices were manufactured in the same manner as in Example 1, except that compounds listed in Table 2 below were each used as a dopant instead of Compound 125 in forming an emission layer.

Evaluation Example 1: Evaluation of Characteristics of Organic Light-Emitting Device

The driving voltage, maximum external quantum efficiency (Max EQE) value (%), and lifespan (LT₉₇, hr) of the organic light-emitting devices manufactured according to Examples 1 to 12 and Comparative Examples A and B were evaluated, and results thereof are shown in Table 2. Here, as a device used for the evaluation, a current-voltage meter (Keithley 2400) and a luminance meter (Minolta Cs-1000A) were used. The lifespan (LT₉₇) (at 3,500 nit) obtained by evaluating time (hr) that lapsed when luminance was 97% of initial luminance (100%), and was indicated in a relative value (%).

TABLE 2 LT₉₇ Compound No. of Driving (relative value, %) dopant in emission layer voltage(V) Max EQE(%) (at 3,500 nit) Example 1  125 4.43 23.3 100 Example 2  128 4.41 23.4  87 Example 3  163 4.42 24.1  93 Example 4  365 4.16 22.3 110 Example 5  505 4.43 23.6 130 Example 6  526 4.47 25.4 150 Example 7  676 4.33 25.8 180 Example 8  806 4.45 23.2 120 Example 9  865 4.10 23.0 100 Example 10 1365 4.38 22.5 110 Example 11 1497 4.35 25.1 165 Example 12 1505 4.48 22.8 170 Comparative A 4.35 19.8  27 Example A Comparative B 4.23 20.5  43 Example B

125

128

163

365

505

526

676

806

866

1366

1497

1505

A

B

Referring to Table 2, it was confirmed that the organic light-emitting device manufactured according to Examples 1 to 12 had a comparable value of driving voltage and improved external quantum efficiency and longer lifespan characteristics, as compared with the organic light-emitting device manufactured according to Comparative Examples A and B.

According to the one or more embodiments, the organometallic compound has excellent electronic characteristics and heat resistance, and thus, an electronic device, for example, an organic light-emitting device, including the organometallic compound may have good driving voltage, good external quantum efficiency, and good lifespan characteristics. In addition, since the organometallic compound has excellent phosphorescence characteristics, a diagnostic composition including the organometallic compound may be provided with a high diagnosis efficiency.

It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments.

While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims. 

What is claimed is:
 1. An organometallic compound represented by Formula 1: M(L₁)_(n1)(L₂)_(n2)  Formula 1 wherein, in Formula 1, M is a transition metal, L₁ is a ligand represented by Formula 2A, L₂ is a ligand represented by Formula 2B, n1 and n2 are each independently 1 or 2, wherein, when n1 is 2, two L₁(s) are identical to or different from each other and when n2 is 2, two L₂(s) are identical to or different from each other, the sum of n1 and n2 is 2 or 3, and L₁ and L₂ are different from each other:

wherein, in Formulae 2A and 2B, Y₁ and Y₄ are each independently C or N, X₁ is Si, X₂₁ is O, S, S(═O), N(Z₂₉), C(Z₂₉)(Z₃₀), or Si(Z₂₉)(Z₃₀), T₁ to T₄ are each independently C, N, carbon linked to ring CY₁, or carbon linked to M in Formula 1, wherein one of T₁ to T₄ is carbon linked to M in Formula 1, and one of the remaining T₁ to T₄ that are not linked to M in Formula 1 is carbon linked to ring CY₁, T₅ to T₈ are each independently C or N, at least one of the remaining T₁ to T₈ that are not carbon linked to M and ring CY₁ is N, provided that, when a group represented by

in Formula 2B is an unsubstituted benzene group, then at least one of the remaining T₅ to T₈ that are not carbon linked to M and ring CY₁ in Formula 2A is N, ring CY₁ and ring CY₁₄ are each independently a C₅-C₃₀ carbocyclic group or a C₁-C₃₀ heterocyclic group, R₂₁ to R₂₃ are each independently a C₁-C₆₀ alkyl group or a C₆-C₆₀ aryl group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₃-C₁₀ cycloalkyl group, a phenyl group or any combination thereof, Z₁, Z₂, Z₂₉, Z₃₀, and R₁₁ to R₁₄ are each independently hydrogen, deuterium, —F, —Cl, —Br, —I, —SF₅, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₁-C₆₀ alkylthio group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₂-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁)(Q₂), —Ge(Q₃)(Q₄)(Q₅), —B(Q₆)(Q₇), —P(═O)(Q₈)(Q₉), or —P(Q₈)(Q₉), wherein R₁₂ is neither hydrogen nor a methyl group, a1 and b1 are each independently an integer from 0 to 20, wherein, when a1 is 2 or more, two or more Z₁(s) are identical to or different from each other, and when b1 is 2 or more, two or more R₁₄(s) are identical to or different from each other, a2 is an integer from 0 to 6, wherein, when a2 is 2 or more, two or more Z₂(s) are identical to or different from each other, two or more of R₂₁ to R₂₃ are optionally linked to form a C₅-C₃₀ carbocyclic group that is unsubstituted or substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic group that is unsubstituted or substituted with at least one R_(10a), two or more of a plurality of Z₁(s) are optionally linked to form a C₅-C₃₀ carbocyclic group that is unsubstituted or substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic group that is unsubstituted or substituted with at least one R_(10a), two or more of a plurality of Z₂(s) are optionally linked to form a C₅-C₃₀ carbocyclic group that is unsubstituted or substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic group that is unsubstituted or substituted with at least one R_(10a), R₁₂ and R₁₃ are optionally linked to form a C₅-C₃₀carbocyclic group that is unsubstituted or substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic group that is unsubstituted or substituted with at least one R_(10a), two or more of a plurality of R₁₄(s) are optionally linked to form a C₅-C₃₀ carbocyclic group that is unsubstituted or substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic group that is unsubstituted or substituted with at least one R_(10a), two or more of Z₁, Z₂ and R₁₁ to R₁₄ are optionally linked to form a C₅-C₃₀ carbocyclic group that is unsubstituted or substituted with at least one R_(10a) or a C₁-C₃₀ heterocyclic group that is unsubstituted or substituted with at least one R_(10a), R_(10a) is the same as defined in connection with R₁₄, * and *′ in Formulae 2A and 2B each indicate a binding site to M in Formula 1, a substituent of the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₁-C₆₀ alkylthio group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₂-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is: deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, or a C₁-C₆₀ alkoxy group, each substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₁₁)(Q₁₂), —Ge(Q₁₃)(Q₁₄)(Q₁₅), —B(Q₁₆)(Q₁₇), —P(═O)(Q₁₈)(Q₁₉), —P(Q₁₈)(Q₁₉), or any combination thereof; a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, or a monovalent non-aromatic condensed heteropolycyclic group, each unsubstituted or substituted with deuterium, —F, —Cl, —Br, —I, —CD₃, —CD₂H, —CDH₂, —CF₃, —CF₂H, —CFH₂, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₂-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —N(Q₂₁)(Q₂₂), —Ge(Q₂₃)(Q₂₄)(Q₂₅), —B(Q₂₆)(Q₂₇), —P(═O)(Q₂₈)(Q₂₉), —P(Q₂₈)(Q₂₉), or any combination thereof; —N(Q₃₁)(Q₃₂), —Ge(Q₃₃)(Q₃₄)(Q₃₅), —B(Q₃₆)(Q₃₇), —P(═O)(Q₃₈)(Q₃₉), or —P(Q₃₈)(Q₃₉); or any combination thereof; Q₁ to Q₉, Q₁₁ to Q₁₉, Q₂₁ to Q₂₉, and Q₃₁ to Q₃₉ are each independently hydrogen; deuterium; —F; —Cl; —Br; —I; a hydroxyl group; a cyano group; a nitro group; an amino group; an amidino group; a hydrazine group; a hydrazone group; a carboxylic acid group or a salt thereof; a sulfonic acid group or a salt thereof; a phosphoric acid group or a salt thereof; a C₁-C₆₀ alkyl group unsubstituted or substituted with deuterium, a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group, or any combination thereof; a C₂-C₆₀ alkenyl group; a C₂-C₆₀ alkynyl group; a C₁-C₆₀ alkoxy group; a C₃-C₁₀cycloalkyl group; a C₁-C₁₀ heterocycloalkyl group; a C₃-C₁₀ cycloalkenyl group; a C₂-C₁₀ heterocycloalkenyl group; a C₆-C₆₀ aryl group unsubstituted or substituted with deuterium, a C₁-C₆₀ alkyl group, a C₆-C₆₀ aryl group, or any combination thereof; a C₆-C₆₀ aryloxy group; a C₆-C₆₀ arylthio group; a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group; or a monovalent non-aromatic condensed heteropolycyclic group.
 2. The organometallic compound of claim 1, wherein M in Formula 1 is Ir, and the sum of n1 and n2 is 3, or M in Formula 1 is Pt, and the sum of n1 and n2 is
 2. 3. The organometallic compound of claim 1, wherein X₂₁ in Formula 2A is O or S.
 4. The organometallic compound of claim 1, wherein Z₁ in Formula 2A is: hydrogen, deuterium, —F, or a cyano group; a C₁-C₂₀ alkyl group unsubstituted or substituted with deuterium, —F, a cyano group, a C₃-C₁₀ cycloalkyl group, a deuterated C₃-C₁₀ cycloalkyl group, a (C₁-C₂₀ alkyl)C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a deuterated C₁-C₁₀ heterocycloalkyl group, a (C₁-C₂₀ alkyl)C₁-C₁₀ heterocycloalkyl group, or any combination thereof; or a C₃-C₁₀ cycloalkyl group or a C₁-C₁₀ heterocycloalkyl group, unsubstituted or substituted with deuterium, —F, a cyano group, a C₁-C₂₀ alkyl group, a deuterated C₁-C₂₀ alkyl group, or any combination thereof.
 5. The organometallic compound of claim 1, wherein a number of carbons included in R₁₂ of Formula 2B is at least two.
 6. The organometallic compound of claim 1, wherein the organometallic compound represented by Formula 1 satisfies at least one of Condition (1) to Condition (3) below: Condition (1) In Formula 2 Å, Z₁ is not hydrogen, and a1 is an integer of 1 to
 20. Condition (2) In Formula 2B, R₁₄ is not hydrogen, and b1 is an integer of 1 to
 20. Condition (3) In Formula 2 Å, Z₂ is not hydrogen, and a2 is an integer of 1 to
 6. 7. The organometallic compound of claim 1, wherein the organometallic compound represented by Formula 1 comprises at least one deuterium, at least one fluoro group (—F), at least one cyano group (—CN), or any combination thereof.
 8. The organometallic compound of claim 1, wherein Z₂ in Formula 2A is not hydrogen, a2 is an integer from 1 to 3, and at least one of Z₂(s) in number of a2 is a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₁-C₆₀ alkylthio group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, or a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.
 9. The organometallic compound of claim 1, wherein a group represented by

in Formula 2A is represented by one of Formulae CY1-1 to CY1-28:

wherein, in Formulae CY1-1 to CY1-28, Z₁₁ to Z₁₄ are each independently the same as defined in connection with Z₁ in claim 1, wherein each of Z₁₁ to Z₁₄ are not hydrogen, ring CY_(10a) is a C₅-C₃₀ carbocyclic group or a C₁-C₃₀ heterocyclic group, R_(10a) is the same as described in claim 1, aa is an integer from 0 to 10, and * indicates a binding site to M in Formula 1, and *″ indicates a binding site to one of T₁ to T₄ in Formula 2 Å.
 10. The organometallic compound of claim 9, wherein a group represented by

in Formula 2A is represented by one of Formulae CY1-4, CY1-7, CY1-9, CY1-11, CY1-12, and CY1-14 to CY1-24.
 11. The organometallic compound of claim 1, wherein a group represented by

in Formula 2A is represented by one of Formulae CY2-1 to CY2-6:

wherein, in Formulae CY2-1 to CY2-6, T₁ to T₈ are each independently C or N, X₂₁ is the same as described in claim 1, *″ indicates a binding site to ring CY₁ in Formula 2A, and *′ indicates a binding site to M in Formula
 1. 12. The organometallic compound of claim 11, wherein a) at least one of T₃ to T₈ in Formulae CY2-1 and CY2-6 is N, b) at least one of T₁, T₂, and T₅ to T₈ in Formulae CY2-2 and CY2-5 is N, c) at least one of T₁ and T₄ to T₈ in Formulae CY2-3 and CY2-4 is N.
 13. The organometallic compound of claim 11, wherein 1) T₁ to T₈ in Formulae CY2-1 to CY2-6 are C; 2) one of T₃ to T₈ in Formula CY2-1 is N, and the remaining T₃ to T₈ that are not N in Formula CY2-1 are C; 3) T₃ and T₈ in Formula CY2-1 are N, and T₄ to T₇ in Formula CY2-1 are C; 4) T₆ and T₈ in Formula CY2-1 are N, and T₃ to T₅ and T₇ in Formula CY2-1 are C; 5) one of T₁, T₂ and T₈ in Formula CY2-2 is N, and the remaining T₁, T₂ and T₅ to T₈ that are not N in Formula CY2-2 are C; 6) T₁ and T₈ in Formula CY2-2 are N, and T₂ and T₅ to T₇ in Formula CY2-2 are C; 7) T₂ and T₈ in Formula CY2-2 are N, and T₁ and T₅ to T₇ in Formula CY2-2 are C; 8) one of T₁, T₄ and T₈ in Formulae CY2-3 and CY2-4 is N, and the remaining T₁, T₄ and T₅ to T₈ that are not N in Formulae CY2-3 and CY2-4 are C; 9) T₁ and T₈ in Formulae CY2-3 and CY2-4 are N, and T₄ and T₅ to T₇ in Formulae CY2-3 and CY2-4 are C; 10) T₄ and T₈ in Formulae CY2-3 and CY2-4 are N, and T₁ and T₅ to T₇ in Formulae CY2-3 and CY2-4 are C; 11) one of T₁ and T₈ in Formula CY2-5 is N, and the remaining T₁, T₂ and T₅ to T₈ that are not N in Formula CY2-5 are C; 12) T₁ and T₈ in Formula CY2-5 are N, and T₂ and T₅ to T₇ in Formula CY2-5 are C; 13) one of T₄ and T₈ in Formula CY2-6 is N, and the remaining T₃ to T₈ that are not N in Formula CY2-6 are C; or 14) T₄ and T₈ in Formula CY2-6 are N, and T₃ and T₅ to T₇ in Formula CY2-6 are C.
 14. The organometallic compound of claim 1, wherein a group represented by

in Formula 2A is represented by one of Formulae CY2-1001 to CY2-1141, CY2-2001 to CY2-2092, CY2-3001 to CY2-3092, CY2-4001 to CY2-4092, CY2-5001 to CY2-5065 and CY2-6001 to CY2-6065:

wherein, in Formulae CY2-1001 to CY2-1141, CY2-2001 to CY2-2092, CY2-3001 to CY2-3092, CY2-4001 to CY2-4092, CY2-5001 to CY2-5065 and CY2-6001 to CY2-6065, X₂₁ is the same as described in claim 1, Z₂₁ to Z₂₈ are each independently the same as defined in connection with Z₂ in claim 1, wherein each of Z₂₁ to Z₂₈ are not hydrogen, *″ indicates a binding site to ring CY₁ in Formula 2 Å, and *′ indicates a binding site to M in Formula
 1. 15. The organometallic compound of claim 1, wherein a group represented by

in Formula 2B is represented by one of Formulae CY14(1) to CY14(63):

wherein, in Formulae CY14(1) to CY14(63), R_(14a) to R_(14d) are each independently the same as defined in connection with R₁₄ in claim 1 wherein each of R_(14a) to R_(14d) are not hydrogen, X₁₄ is C(R₁)(R₂), N(R₁), O, S, or Si(R₁)(R₂), R₁ to R₈ are each the same as defined in connection with R₁₄ in claim 1, *″ indicates a binding site to a carbon atom of a neighboring pyridine ring in Formula 2B and *′ indicates a binding site to M in Formula
 1. 16. An organic light-emitting device comprising: a first electrode, a second electrode; and an organic layer disposed between the first electrode and the second electrode and comprising an emission layer, wherein the organic layer comprises at least one organometallic compound of claim
 1. 17. The organic light-emitting device of claim 16, wherein the first electrode is an anode, the second electrode is a cathode, and the organic layer further comprises a hole transport region disposed between the first electrode and the emission layer and an electron transport region disposed between the emission layer and the second electrode, wherein the hole transport region comprises a hole injection layer, a hole transport layer, an electron blocking layer, a buffer layer, or any combination thereof, and the electron transport region comprises a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.
 18. The organic light-emitting device of claim 16, wherein the emission layer comprises the at least one organometallic compound.
 19. The organic light-emitting device of claim 18, wherein the emission layer further comprises a host, and an amount of the host is greater than that of the organometallic compound.
 20. An electronic apparatus comprising the organic light-emitting device of claim
 16. 